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The Home Medical Library
The Home Medical Library
By
Kenelm Winslow, B.A.S., M.D.
Formerly Assistant Professor Comparative Therapeutics, Har- vard University ; Late Surgeon to the Newton Hospital ; Fellow of the Massachusetts Medical Society, etc.
With the Cooperation of Many Medical Advising Editors and Special Contributors
IN SIX VOLUMES
First Aid :: Family Medicines :: Nose, Throaty Lungs, Eye, and Ear :: Stomach and Bowels :: Tumors and Skin Diseases :: Rheumatism :: Germ Diseases Nervous Diseases :: Insanity :: Sexual Hygiene Woman and Child :: Heart, Blood, and Diges- tion :: Personal Hygiene :: Indoor Exercise Diet and Conduct for Long Life :: Prac- tical Kitchen Science :: Nervousness and Outdoor Life :: Nurse and Pa- tient :: Camping Comfort :: Sani- tation of the Household :: Pure Water Supply :: Pure Boo d^^^^^ Stable and Kenttel
SHP 3 : {993I
The Review of Reviews ComTpai
1907
Medical Advising Editors
Managing Editor Albert W^arren Ferris, A.M., M.D.
Former Assistant in Neurology, ColumMa University ; Former Chairman, Section on
Neurology and Psychiatry, New York Academy of Medicine ; Assistant in
Medicine, University and Bellevtce Hospital Medical College;
Medical Editor, New hiternatiortal Encyclopedia.
Nervous Diseases Charles E. Atwood, M.D.
Assistant in Neurology, Colutnbia University ; Former Physician, Utica Staie Hospital and Bloomingdale Hospital for Insane Patients ; Former Clinical Assist- ant to Sir William, Cowers, National Hospital, London.
Pregnancy Russell Bellamy, M.D.
Assistant in Obstetrics and Gynecology, Cornell University Medical College Dispensary;
Captain and Assistant Surgeon {in charge^, Squadron A, New York
Cavalry ; Assistant in Surgery, New York Polyclinic.
Germ Diseases Hermann Michael Biggs, M.D.
General Medical Officer and Director of Bacteriological Laboratories, New York City
Department of Health ; Professor of Clifiical Medicine in University and
Bellevue Hospital Medical College ; Visiting Physician to Bellevue,
St. Vincent's, Willard Parker, and Riverside Hospitals.
The Eye and Ear J. Herbert Claiborne, M.D.
Clinical Instructor in Ophthalmology, Cornell University Medical College; Former A d- junct Professor of Ophthalmology , New York Polyclinic; Former Instructor in Ophthal- mology in Columbia University; Surgeon, New A msterdam Eye and Ear Hospital.
Sanitation Thomas Darlington, M.D.
Health Commissioner of New York City; Former President Medical Board, New^ York Foufidling Hospital; Consulting Physician, French Hospital; A ttending Physician, St. John's Riverside Hospital, Yonkers; Surgeon to New Croton Aqueduct and other Public Works, to Copper Queen Consolidated Mining Com- pany of Arizona, and Arizona and Southeastern Railroad Hospital; A uthor of Medical and Clitnatological Works.
Menstruation Austin Flint, Jr., M.D.
Professor of Obstetrics and Clinical Gynecology, New York University and Bellevue Hos- pital Medical College; Visiting Physician, Bellevue Hospital; Consulting Obstetri- cian, New York Maternity Hospital; Attending Physician, Hospital for Rup- tured and Crippled, Manhattan Maternity and Emergency Hospitals.
Heart and Blood John Bessner Ruber, A.M., M.D.
Assistant in Medicine, University and Bellevue Hospital Medical College; Visiting Phy- sician to St. Joseph's Home for Consu/npiives; Author of " Consutnption: Its Relation to Man and His Civilization; Its Prevention and Cure,'*
Skin Diseases James C. Johnston, A.B., M.D.
Instructor in Pathology and Chief of Clinic, Department of Dermatology, Cornell Uni- versity Medical College.
Diseases of Children Charles Gilmore Kerley, M.D.
Professor^ of Pediatrics, New York Polyclinic Medical School and Hospital; A ttending
Physician, New York Infant A sylum. Children'' s Departm.ent of Sydenham Hospital,
and Babies' Hospital, N. Y,; Consulting Physician, Hojne for Crippled Children.
Bites and Stings George Gibier Rambaud, M.D.
President, New York Pasteur Institute.
Headache Alonzo D. Rockwell, A.M., M.D.
Former Professor Electro-Therapeutics and Neurology at New York Post-Graduate
Medical School; Neurologist and Electro- Therapeutist to the Flushing Hospital;
Former Electro-Therapeutist to the Woman's Hospital in the State of
New York; Author of Works on Medical and Surgical Uses
of Electricity, Nervous Exhaustion (Neurasthenia), etc.
Poisons E. Ellsworth Smith, M.D.
Pathologist, St. John's Hospital, Yonkers; Somerset Hospital, Somerville, N. J.; Trinity
Hospital, St. Bartholomew's Clinic, and the New York
West Side German Dispensary.
Catarrh Samuel Wood Thurber, M.D.
Chief of Clinic and Instructor in Laryngology, Columbia University: Laryngologist to the Orphan's Home and Hospital.
Care of Infants Herbert B. Wilcox, M.D.
Assistafit in Diseases of Children, Columbia University .
special Contributors
Food Adulteration S. Josephine Baker, M.D.
Medical Inspector, New York City Department of Health.
Pure Water Supply William Paul Gerhard, C.E.
Consulting Engitteer for Sanitary Works; Metnber of American Public Health Associa- tion ; Member, Ainerican Society Mecha?iical Efigineers ; Corresponding Member of American Institute of Architects, etc.; Author of "■' House Drainage," etc.
Care of Food Janet McKenzie Hill
Editor, Boston Cooking School Magazine.
Nerves and Outdoor Life S. Weir Mitchell, M.D., LL.D.
LL.D. {Harvard, Edinburgh, Princeton^; Former President, Philadelphia College of Physicians; Member, National Academy of Sciences, Association of American Physi- cians, etc.; Author of essays: "Injuries to Nerves?' '^ Doctor and Patient," "Fat and Blood" etc.; of scientific works: "Researches Upon tJie Venom, of the Rattlesnake," etc.; oftiovels: "Hugh Wynne," "Characteristics," "Constance Trescott," "The Adventures of Francois" etc.
Sanitation George M. Price, M.D.
Former Medical Sanitary Inspector, Departtnent of Health, New York City; Inspector,
New York Sanitary Aid Society of the roth Ward, 1885; Manager, Model
Tenement-houses of the New York Te?iement- house Building Co., 1888;
Inspector, New York State Tenetnent- house Comtnission, i8qs; Author
of " Tenement-house Inspection," "Handbook on Sanitation," etc.
Indoor Exercise Dudley Allen Sargent, M.D.
Director of Hemenway Gymnasium, Harvard University; Former President, A merican Physical Culture Society; Director, Normal ScJtool of Physical Training, Cam- bridge, Mass.; Presidetit, American Association for Promotion of Physical Education; Author of "Universal Test for Strength," "Healthy Strength and Power ," etc.
Long Life Sir Henry Thompson, Bart., F.R.C.S., M.B. (Lond.)
Surgeon Extraordinary to His Majesty the King of the Belgians; Consulting Surgeon to University College Hospital, London; Etneritus Professor of Clin- ical Surgery to University College, London, etc.
Camp Comfort Stewart Edward White
Author of " The Forest," " The Mountains," " The Silent Places," " The Blazed Trail," etc.
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WALTER REED.
In the year 1900, Major Walter Reed, a surgeon in the United States Army, demonstrated, by experiments conducted in Cuba, that a mosquito of a single species, Stegomyia fasciata, which has sucked the blood of a yellow-fever patient, may transmit the disease by biting another person, but not until about twelve days have elapsed. He also proved, as described in Volume I, Part II, that the malady is not contagious. " With the exception of the dis- covery of anaesthesia," said Professor Welch, of Johns Hopkins University, " Dr. Reed's researches are the most valuable contribu- tions to science ever made in this country." General Leonard Wood declared the discovery to be the " greatest medical work of modern times," which, in the words of President Roosevelt, "ren- ders mankind his debtor." Major Reed died November 23, IQ02.
4
The Home Medical -- Library
v- .5
VOLUME V :: SANITATION
Edited by
Thomas Darlington, M.D.
Health Commissioner of New York City; Former President Medical
Board, New York Foundling Hospital, etc. ; Author of
Medical and Climatological Works
WATER SUPPLY AND PURIFICATION
By WILLIAM PAUL GERHARD, C.E.
Consulting Engineer for Sanitary Works; Author of "House Drain- age,^'' "Sanitary Engineering,''^ "Household Wastes," etc.
PURE FOOD FOR THE HOUSEKEEPER
By S. JOSEPHINE BAKER, M.D.
Medical Inspector, New York City Department of Health
THE HOUSE AND GROUNDS
By GEORGE M. PRICE, M.D.
Former Medical Sanitary Inspector, Department of Health, New
York City ; Author of " Tenement- House Inspection,'**
"Handbook on Sanitation,''^ etc.
New York The Review of Reviews Company
1907
Copyright, 1907, by The Review of Reviews Company
THE TROW PRESS, NEW YORK
Contents PART I
CHAPTER PAGE
I. Country Sources of Water Supply . 19 Relation of Water to Health — Collection of Rain Water — Cisterns — Springs — Various Kinds of Wells — Laws Regulating Supply.
II. Appliances for Distributing Water . 39 Pumping Machines — The Hydraulic Ram — Use of Windmills — Engines — Steam and Electric Pumps — Reservoirs and Tanks — ^Appliances for Country Houses.
III. Purifying Water by Copper Sulphate 52 Clear Water Often Dangerous — Pollution Due to Plants — Copper Sulphate Method — Directions for the Copper Cure.
IV. Ridding Stagnant Water of Mosqui-
toes 70
Malaria Due to Mosquitoes — Cause of Yel- low Fever — Effect of a Mosquito Bite — Destruction of Larvae — Best Preventive Measures — Use of Kerosene.
PART II
I. How to Detect Food Adulteration . 87 Definition of Adulteration — Food Laws —
Contents
CHAPTER PAGE
Permissible Adulterants — How to Select Pure Food — Chemical Tests.
II. Mushroom Poisoning . . . .112 Symptoms and Treatment — Coffee and Atropine the Best Antidotes — How to Tell the Edible Kind—" Horse," " Fairy-ring/' and Other Varieties — Poisonous Species.
PART III
I. Soil and Sites 131
Constituents of the Soil — Influence on Health — Improving Defective Soil — Street Paving and Tree Planting — Proper Con- struction of Houses — Subsoil Drainage.
II. Ventilation 146
What is Meant by Ventilation — Quantity of Air Required — Natural Agents of Ven- tilation— Special Appliances.
III. Warming 160
Various Alethods — Materials of Combus- tion— Chimneys — Fireplaces and Grates — Stoves — Hot-air Warming — Hot-water Systems — Principles of Steam Heating.
IV. Disposal of Sewage 170
Refuse and Garbage — Discharge into Wa- ters— Cremation — Precipitation — Inter- mittent Filtration — Immediate Disposal, etc.
10
Contents
CHAPTER PAGE
V. Sewers . . . . . . . 182
Definition — Materials Used in Construc- tion— Levels of Trenches — Joints of Pipes — The Fall and Flow of the Contents — Connections — Tide Valves — Sewer Gas.
VI. Plumbing 189
Purposes and Requisites — Materials Used
— Joints and Connections — Construction of Traps — Siphonage and Back Pressure — The Vent-pipe System.
VII. Plumbing Pipes 206
Construction of House Drains — Fall, Po- sition, and Connection — Main Traps — Ex- tension of Vertical Pipes — Fresh-air Inlets
— Soil and Waste Pipes — Branch Pipes, etc.
VIII. Plumbing Fixtures 216
Sinks — Washbasins — Washtubs — Bath- tubs — Refrigerators, etc. — Safes and Wastes — Pan, Valve, and Hopper Closets
— Flush Tanks — Yard Closets — Drains.
IX. Defects in Plumbing . . . .231 Poor Work — Improper Conditions — How
to Test Traps, Joints, and Connections
— Detect Sewer Gas — Water-pressure, Smoke, and Scent Tests — Special Appli- ances.
II
Contents
CHAPTER PAGE
X. Infection and Disinfection . . , 238 Physical and Chemical Disinfectants — Use of Sulphur Dioxide — Formaldehyde — Hydrocyanic Acid — Chlorine — Carbolic Acid — Bichloride of Mercury — Formalin — Potassium Permanganate, etc.
XL Cost of Conveyed Heating Systems . 254 Cost of Hot-air Systems — Cast-iron Hot- water Heater — Advantages and Disadvan- tages — Cost for a Ten-room House — Steam Heating — Cost of Equipment.
12
The Editor's Preface
The character and scope of this volume render it a most useful book for the home maker. The question of sanitation is one that closely affects the life of each individual, and many of its aspects are treated here in a lucid and comprehensive manner. Designed for wide distribution, these articles have been written to meet the needs of the dweller in the more densely populated communities, as well as those living in the less thickly settled portion of the country.
In large cities the water supply is a problem that is cared for by regularly constituted sanitary author- ities. Pure water is a vital necessity, but the inhabitant of a city has no need to personally concern himself with the source of supply. In the country, however, the home builder must often decide the matter for him- self, and it is the aim of this book to give him the needed directions for avoiding many errors and pitfalls that abound in this direction.
House construction, with its intricate problems, is also a more serious matter for the country dweller than for his city brother.
In the matter of food supply, the inhabitant of a country district is more fortunate. Fresh vegetables
13
The Editor's Preface
and dairy products are much more easily obtained, and their freshness and purity more dependable.
The article on water supply by Mr. Gerhard is au- thoritative, written, as it is, by a most eminent san- itarian. The publishers are to be congratulated upon the following valuable contribution to the same sub- ject as regards the use of copper sulphate and the con- cise presentation of plans for mosquito extermination, while the extended work of Dr. Price and Dr. Baker's " Food Adulteration " are much to be commended. The two latter have been connected with the Depart- ment of Health of New York City, and have the ad- vantage of experience in an organization which gives to the citizens of New York the protection to health that the wise use of science, knowledge, and money afford.
I trust that the notes I have added in the light of recent practice of the New York City Department of Health may make this material of the utmost practical value to the householder of to-day.
Through this Department of Health, New York City spent, during 1905, over $1,500,000, and for 1906 it has appropriated over $1,800,000. This vast sum of money is used for the sole purpose of safeguard- ing its citizens from disease. Sanitation in its varied branches is pursued as an almost exact science, and the efforts of trained minds are constantly employed in combating disease and promoting sanitation.
The cities care for their own, but the greater num-
14
The Editor's Preface
ber of the inhabitants of this country must rely upon their individual efforts. Therefore, any dissemination of knowledge regarding sanitation is most worthy. This book has a useful mission. It is pregnant with helpful suggestions, and I most heartily commend its purpose and its contents.
Thomas Darlington, President of the Board of Health, New York City.
15
Part I
WATER SUPPLY AND PURIFICATION
BY WILLIAM PAUL GERHARD
CHAPTER I Country Sources of Water Supply
The writer was recently engaged to plan and in- stall a water-supply system for a country house which had been erected and completed without any provision whatever having been made for supplying the build- ings and grounds with water. The house had all the usual appointments for comfort and ample modern conveniences, but these could be used only with water borrowed from a neighbor. In all parts of the coun- try there are numerous farm buildings which are with- out a proper water-supply installation. These facts are mentioned to emphasize the importance of a good water supply for the country home, and to point out that water is unquestionably the most indispensable require- ment for such structures.
Adequate Water Supply Important
But the advantages of a water supply are not limited to the dwelling house, for it is equally useful on the farm, for irrigation, and in the garden, on the golf grounds and tennis courts, in the barns and stables;
19
Country Water Supply
it affords, besides, the best means for the much-desired fire protection. And, most important of all, an un- stinted and adequate use of water promotes cleanliness and thereby furthers the cause of sanitation, in the country not less than in the city home.
The water supply for country houses has been so often discussed recently that the writer cannot hope to bring up any new points. This article should, therefore, be understood to offer simple suggestions as to how and where water can be obtained, what water is pure and fit for use, what water must be considered with suspicion, what water is dangerous to health, and how a source of supply, meeting the requirements of health, can be made available for convenient use.
Right here I wish to utter a warning against the frequent tendency of owners of country houses to play the role of amateur engineers. As a rule this leads to failure and disappointment. Much money uselessly spent can be saved if owners will, from the beginning, place the matter in experienced hands, or at least seek the advice of competent engineers, and adopt their suggestions and recommendations as a guide.
Points to he Borne in Mind
Many are the points to be borne in mind in the search for water. Science teaches us that all water comes from the clouds, the atmospheric precipitation being in the form of either rain, or dew, or snow.
20
William Paul Gerhard
After reaching- the earth's surface, the water takes three different courses, and these are mentioned here be- cause they serve to explain the different sources of supply and their varied character.
A part of the water runs off on the surface, forming brooks, streams, and lakes, and if it falls on roofs of houses or on prepared catchment areas, it can be col- lected in cisterns or tanks as rain water. Another part of the water soaks away into pervious strata of the subsoil, and constitutes underground water, which be- comes available for supply either in springs or in wells. A third part is either absorbed by plants or else evap- orated.
In our search for a source of supply, we should always bear in mind the essential requirements of the problem. Briefly stated, these are : the wholesomeness of the water, the adequateness and steadiness of the supply, its availability under a sufficient pressure, in- suring a good flow, and the legal restrictions with which many water-supply problems are surrounded.
The first essential requirement is that of whole- someness. The quality of a water supply is dependent upon physical properties and upon chemical and bac- teriological characteristics. Water, to be suitable for drinking, must be neither too hard nor too soft; it should not contain too many suspended impurities, nor too much foreign matter in solution. Pure water is colorless and without odor. But it must be under- stood that the quality cannot be decided merely by
21
Country Water Supply
the color, appearance, taste, and odor. The chemical and bacteriological examinations, if taken together, form a much safer guide, and with these analyses should go hand in hand a detailed survey of the water source and its surroundings.
Relation of Water to Health
Any pronounced taste in the water renders it sus- picious ; an offensive smell points to organic contamina- tion; turbidity indicates presence of suspended im- purities, which may be either mineral or organic. But even bright and sparkling waters having a very good taste are sometimes found to be highly polluted. Hence, it should be remembered that neither bright appearance nor lack of bad taste warrants the belief that water is free from dangerous contamination.
It is a well-established fact now that there is a relation between the character of the water supply and the health of a community ; and what is true of cities, villages, and towns, is, of course^ equally true of the individual country house.
How Water Becomes Contaminated
There are numerous ways in which water may be- come polluted, either at the source or during storage or finally during distribution. Rain water, falling pure from the clouds, encounters dust, soot, decaying leaves
22
William Paul Gerhard
and other vegetable matters, and ordure of birds on the roofs; its quahty is also affected by the roofing ma- terial, or else it is contaminated in the cisterns by leak- age from drains or cesspools. Upland waters contain generally vegetable matter, while surface water from cultivated lands becomes polluted by animal manure. River water becomes befouled by the discharge into it of the sewers from settlements and towns located on its banks. Subsoil water is liable to infiltration of solid and liquid wastes emanating from the human system, from leaky drains, sewers, or cesspools, stables, or farmyards; and even deep well water may become contaminated by reason of defects in the construction of the well.
During storage, water becomes contaminated in open reservoirs by atmospheric impurities; a growth of vegetable organisms or algse often causes trouble, bad taste, or odor; water in open house tanks and in cisterns is also liable to pollution. During distribu- tion, water may become changed in quality, owing to the action of the water on the material of the pipes.
From what source shall good water be obtained? This is the problem which confronts many of those who decide to build in the country.
The usual sources, in their relative order of purity, are: deep springs and land or surface springs, located either above or below the house, but not too near to settlements; deep subterranean water, made available by boring or drilling a well; upland or mountain
23
Country Water Supply
brooks from uninhabited regions; underground water in places not populated, reached by a dug or driven well; lake water; rain water; surface water from cul- tivated fields; pond and river water; and finally, least desirable of all, shallow well water in villages or towns. These various sources of supply will be considered farther on.
An Ample Volume Necessary
The second essential requirement is ample quantity. The supply must be one which furnishes an ample volume at all seasons and for all purposes.
What is a reasonable daily domestic consumption? The answer to this question necessarily depends upon the character of the building and the habits and oc- cupation of its inmates. It is a universal experience that as soon as water is introduced it is used more lavishly, but also more recklessly and regardless of waste. For personal use, from twenty to twenty-five gallons per person should prove to be ample per day : this comprises water for drinking and cooking, for washing clothes, house and kitchen utensils, personal ablutions, and bathing; but, taking into account other requirements on the farm or of country houses, we require at least sixty gallons per capita per diem. To provide water for the horses, cows, sheep, for carriage washing, for the garden, for irrigation of the lawn, for fountains, etc., and keep a suitable reserve in case
24
William Paul Gerhard
of fire, the supply should be not less than 150 gallons per person per day.
A Good Pressure Required
The third essential requirement is a good water pressure. Where a suitable source of water is found, it pays to make it conveniently available, so as to avoid carrying water by hand, which is troublesome and not conducive to cleanliness. A sufficient pressure is at- tained by either storing water at, or lifting it to, a suitable elevation above the point of consumption. In this respect many farm and country houses are found to be but very imperfectly supplied. Often the tank is placed only slightly higher than the second story of the house. As a result, the water flows sluggishly at the bathroom faucets, and, in case of fire, no effec- tive fire stream can be thrown. Where a reservoir is suitably located above the house, the pressure is sometimes lost by laying pipes too small in diameter to furnish an ample stream. Elevated tanks should always be placed so high as to afford a good working pressure in the entire system of pipes. Where a tower of the required height is objectionable, either on ac- count of the cost or on account of appearance, pressure tanks may be installed which have many advantages.
In selecting a source of water supply, the follow- ing points should be borne in mind for guidance : first, the wholesomeness of the water; next, the cost required
25
Country Water Supply
to collect, store, and distribute the water; finally, where a gravity supply is unavailable, the probable operating expenses of the water system, cost of pumping, etc.
Collection of Rain Water The collection of rain water near extensive manu- facturing establishments is not advisable, except where arrangements are provided for either filtering or dis- tilling the water. In the country, rain water is pure and good, if the precaution is observed to allow the first wash from roofs to run to waste. The rain may be either caught on the roofs, which must always have a clean surface and clean gutters, or else on artificially prepared catchment areas. As an example, I quote: " All about the Bermuda Islands one sees great white scars on the hill slopes. These are dished spaces, where the soil has been scraped ofif and the coral rock exposed and glazed with hard whitewash. Some of these are a quarter acre in size. They catch and carry the rain- fall to reservoirs, for the wells are few and poor, and there are no natural springs and no brooks." (Mark Twain, " Some Rambling Notes of an Idle Excur- sion.")
After the close of the Boer War the English sent about 7,000 Boer prisoners of war to Bermuda, where they were encamped on some of the smaller islands of the group, and the entire water supply for the encamp- ment was obtained by building artificial catchment areas as described in the above quotation.
26
William laid Gerhard
Somet nes, instead of building underground cis- terns, rain water is caught and stored in barrels above ground; if so, these should always be well covered, not only to avo.d pollution, but to prevent the barrels from becoming mosquito breeders. Cisterns should always be built with care and made water-tight and impervi- ous. The walls should be lined with cemented brick- work. In soil consisting of hard pan, cisterns in some parts of the country are built without brick walls, the walls of the excavation being simply cemented. I do not approve of such cheap construction, particularly where the cistern is located near a privy or cesspool. Pollution of cistern v^ater is often due to the cracking of the cement lining. Overflows of cisterns should never be connected with a drain, sewer, or cesspool. Run the overflow into some surface ditch and provide the mouth with a fine wire screen, to exclude small animals. It is not recommended to build cisterns in cellars of houses.
Quality of Water Obtained from Lakes
Lakes yield, as a rule, a supply of clear, bright, and soft water. This is particularly the case with moun- tain lakes, because they are at a distance from sources of contamination. The character of the water depends upon whether the lake is fed by brooks, that is, by the rain falling upon the watershed, or also by springs. In one case the water is surface water exclusively; in the other, it is surface and underground water
27
Country Pf ater Supply
mixed- The purity also depends upon tb^ depth o£ the lake and upon the character of its bottom.
Deep lakes furnish a better supply and clearer wa- ter than shallow ones. The solid matter ti-ought into the lake by the brooks or rivers which feed it does not remain long in suspension, but soon settles at the bottom, and in this way some lakes acquire the won- derfully clear water and the beautiful bluish-green color for which they are far famed.
Strong Winds Dangerous on Lakes
Strong winds or currents at times stir up the mud from the bottom; hence, in locating the intake, the direction of the prevailing winds should be considered, if practicable. The suction pipe should always be placed in deep water, at a depth of at least fifteen to twenty feet, for here the water is purer and always cooler.
Settlements on the shores of a lake imply danger of sewage contamination, but the larger the lake, the less is the danger of a marked or serious pollution, if the houses are scattered and few.
Pools and stagnant ponds are not to be recom- mended as a source of supply. In artificially made lakes there is sometimes danger of vegetable pollution, and trouble with growth of algse. The bottom of such lakes should always be cleared from all dead vegeta- tion.
28
William Paul Gerhard
Surface water may be obtained from brooks flow- ing through uninhabited upland or from mountain streams. Such water is very pure and hmpid,. par- ticularly where the stream in its downward course tumbles over rocks or forms waterfalls. But, even then, the watershed of the stream should be guarded to prevent subsequent contamination. Larger creeks or rivers are not desirable as a source of supply, for settlements of human habitations, hamlets, villages, and even towns are apt to be located on the banks of the river, which is quite generally used — wrong as it is — as an outlet for the liquid wastes of the community, thus becoming in time grossly polluted. Down-stream neighbors are sure to suffer from a pol- lution of the stream, which the law should prevent.
The Water of Springs
The water of springs is subterranean, or ground water, which for geological reasons has found a natural outlet on the surface. We distinguish two kinds of springs, namely, land or surface springs, and deep springs. The former furnish water which origi- nally fell as rain upon a permeable stratum of sand or gravel, underlaid by an impervious one of either clay or rock. Such water soaks away underground until it meets some obstacle causing it to crop out on the surface. Such spring water is not under pressure and therefore cannot again rise. Water from
29
Country Water Supply
deep springs is rain water fallen on the surface of a porous stratum on a high level, and which passes under an impermeable stratum, and thus, being under pressure, rises again where an opening is encountered in the impervious stratum; these latter springs are really artesian in character.
Deep-spring water is less apt to be polluted than water from surface or land springs, for it has a chance in its flow through the veins of the earth to become filtered. Land springs always require careful watch- ing, particularly in inhabited regions, to prevent sur- face contamination.
Not all Spring Water Pure
It is a popular fallacy that all spring water is ab- solutely pure and healthful. The above explanation will be helpful in pointing out how, in some cases, spring water may be nothing but contaminated ground water. Land springs in uncultivated and uninhabited regions, particularly in the mountains, yield a good and pure supply. But it is always advisable, when tapping a spring for water supply, to study its prob- able source, and carefully to inspect its immediate surroundings. The spring should be protected by constructing a small basin, or reservoir, and by build- ing a house over this. The basin will also serve to store the night flow of the spring. Before deciding upon a supply from a spring, its yield should be ascer-
30
William Paul Gerhard
tained by one of the well-known gauging methods. Springs are usually lowest in the months of October and November, though there is some difference in this respect between land springs and deep springs. The minimum yield of the spring determines whether it forms a supply to be relied upon at all times of the year.
If the spring is located higher than the grounds and buildings to be supplied, a simple gravity supply line may be carried from it, with pipes of good size, thus avoiding undue friction in the line, and stoppages. If lower than the house, the water from the spring must be raised by some pumping method.
All water found underground owes its origin to the rainfall. If concealed water is returned to the sur- face by natural processes it is called spring water, but if recovered by artificial means it is called well water.
Different Kinds of Wells
There are numerous kinds of wells, distinguished from one another by their mode of construction, by their depth from the surface, by the fact of their pierc- ing an impervious stratum or merely tapping the first underground sheet of water, and by the height to which the water in them rises or flows. Thus we have shal- low and deep wells, horizontal wells or infiltration galleries, open or dug wells, tube wells, non-flowing and flowing wells, bored, drilled, and driven wells, tile- lined and brick-lined wells, and combination dug-and- tubular wells.
31
Country Water Supply
When it is desired to provide a water supply by means of wells some knowledge of the geology of the region, of the character of the strata and of their di- rection and dip, will be very useful. In the case of deep wells, it is really essential. By making inquiries as to similar well operations in the neighborhood, one may gain some useful information, and thus, to some extent, avoid guesswork. When one must drill or bore through rock for a very deep well, which neces- sarily is expensive, much money, often uselessly spent, may be saved by consulting the reports of the State geologist, or the publications of the United States Geological Survey, or by engaging the services of an expert hydrogeologist.
'' Water Finders "
It useid to be a common practice to send for so- called " water finders," who being usually shrewd ob- servers would locate by the aid of a hazel twig the exact spot where water could be found. In searching for water one sometimes runs across these men even to-day. The superstitious faith in the power of the forked twig or branch from the hazelnut bush to in- dicate by its twisting or turning the presence of under- ground water was at one time widespread, but only the very slightest foundation of fact exists for the belief in such supernatural powers.
In Europe, attention has again, during the past years, been called to this *' method " of finding water,
32
JVilliam Paul Gerhard
and it has even received the indorsement of a very high German authority in hydrauHc engineering, a man well up in years, with a very wide practical ex- perience, and the author of the most up-to-date hand- book on " Water Supply," but men of science have not failed to contradict his statements.
Definition of " Ground-water Level "
Water percolating through the soil passes down- ward by gravity until it reaches an impervious stra- tum. The surface of this underground sheet of water is technically called " water table " or ground-water level. The water is not at rest, but has a slow and well-defined motion, the rate of which depends upon the porosity of the soil and also upon the inclination or gradient of the water table. A shallow well may be either excavated or driven into this subsoil sheet of water. In populous districts, in villages, towns, but also near habitations, the soil from which water is ob- tained must, of necessity, be impregnated with organic waste matter. If, in such a surface well, the level of the water is lowered by pumping, the zone of pol- lution is extended laterally in all directions. Ordinary shallow well water should always be considered '* sus- picious water." There are two distinct ways in which surface wells are contaminated : one is by leakage from cesspools, sewers, privies, etc. ; the other, just as im- portant and no less dangerous, by direct contamination
33
Country Water Supply
from the surface. The latter danger is particularly great in wells which are open at the surface, ^nd from which water is drawn in buckets or pails. A pump well is always the safer of the two. Frogs, mice, and other small animals are apt to fall into the water; dust and dirt settle into it; the wooden curb and the rotten cover also contribute to the pollution; even the draw-buckets add to it by reason of being often han- dled with unclean hands.
Always avoid, in the country, drinking water from farmers' wells located near cesspools or privies. Such shallow wells are particularly dangerous after a long- protracted drought. It is impossible to define by meas- urement the distance from a cesspool or manure pit at which a well can be located with safety, for this depends entirely upon local circumstances. Contam- ination of shallow wells may, in exceptional cases, be avoided by a proper location of the well with refer- ence to the existing sources of impurity. A well should always be placed above the source of pollution, using the word " above " with reference to the direction in which the ground water flows.
Precautions Regarding Wells
Other precautions to be observed with reference to surface wells are the following :
Never dig a well near places where soil contamina- tion has taken or is taking place. Line the sides of the
34
William Paul Gerhard
well with either brick, stone, or tile pipe, cemented in a water-tight manner to a depth of at least twenty feet from the surface, so that no water can enter except from the bottom, or at the sides near the bottom.
Raise the surface at the top of the well above the grade; arrange it so as to slope away on all sides from the well ; cover it with a flagstone, and cement the same to prevent foreign matters from dropping into the well ; make sure that no surface water can pass directly into the well; make some provision to carry away waste water and drippings from the well.
Shallow wells made by driving iron tubes with well points into the subsoil water are preferable to dug wells. Use a draw-pump in preference to draw buckets.
When a well is sunk through an impervious stra- tum to tap the larger supply of water in the deeper strata, we obtain a "deep well." Water so secured is usually of great purity, for the impurities have been filtered and strained out by the passage of the water through the soil. Moreover, the nature of the con- struction of deep wells is such that they are more efficiently protected against contamination, the sides being made impervious by an iron-pipe casing. In some rare cases, even deep wells show pollution due to careless jointing of the lining, or water follows the outside of the well casing until it reaches the deeper water sheet. Deep wells usually yield more water than shallow driven wells, and the supply increases perceptibly when the water level in the well is lowered
35
Country Water Supply
by pumping. While surface wells draw upon the rain- fall percolating in their immediate vicinity, deep wells are supplied by the rainfall from more remote dis- tricts. Deep wells are either non-flowing or flowing wells. When the hydrostatic pressure under which the water stands is sufficient to make it flow freely out on the surface or at the mouth of the well, we have a flowing, or true artesian well.
Character of Water From Deep Wells
Water from deep wells is of a cool and even tem- perature. It is usually very pure, but in some cases made hard by mineral salts in the water. Sulphur is also at times present, and some wells on the southern Atlantic coast yield water impregnated with sulphur gases, which, however, readily pass off, leaving the water in good condition for all uses. In many cases the water has a taste of iron. No general rule can be quoted as to the exact amount of water which any given well will yield, for this depends upon a number of factors. Increasing the diameter of very deep wells does not seem to have any marked effect in increasing the supply. Thus, a two-foot well gives only from fifteen to thirty per cent more water than a three-inch- pipe well. This rule does not seem to apply to shallow wells of large diameter, for here we find that the yield is about in proportion to the diameter of the well.
It is interesting to note the fact that wells located
36
William Paul Gerhard
near the seashore, within the influence of the tide, vary in the hourly flow. According to Dr. Honda, of the University of Tokio, there is '' a remarkable concord- ance between the daily variations in the level of the tides and the water level in wells." The water in wells one mile from the seashore was found to stand highest at high tide. The daily variation amounted to sixteen centimeters, or a little over six inches. A similar vari- ation was observed by the writer in some flowing wells located on the north shore of Long Island. Dr. Honda found also that the water level in wells varied with the state of the barometer, the water level being low- ered with a rise in the barometer.
Where a large supply is wanted a series of wells may be driven, and, as the expense involved is consid- erable, it is always advisable to begin by sinking a smaller test well to find out whether water may be had.
Ground water may also be recovered from water- bearing strata by arranging horizontal collecting gal- leries with loose- jointed sides through which the water percolates. Such infiltration galleries have been used in some instances for the supply of towns and of manufacturing establishments, but they are not common for the supply of country houses.
Laws Regulating Appropriation of Water
Persons contemplating the establishment of a system of water supply in the country should bear in mind that the taking of water for supply purposes is,
37
Country Water Supply
in nearly all States, hemmed In by legal restrictions. The law makes a distinction between subterranean waters, surface waters flowing in a well-defined chan- nel and within definite banks, and surface waters merely spread over the ground or accumulated in natural depressions, pools, or in swamps. There are separate and distinct laws governing each kind of water. It is advisable, where a water-supply problem presents itself, to look up these laws, or to consult a lawyer well versed in the law of water courses.
If it is the intention to take water from a lake, the property owner should make sure that he owns the right to take such water, and that the deed of his property does not read "to high-water mark only." The owner of a property not abutting on a lake has no legal right to abstract some of the water from the lake by building an infiltration gallery, or a vertical well of large diameter intended for the same purpose. On the other hand, an owner may take subterranean water by driving or digging a well on his own prop- erty, and it does not matter, from the law's point of view, whether by so doing he intercepts partly or wholly the flow of water in a neighboring well. But, if it can be shown that the subterranean water flows in a well-defined channel, he is not permitted to do this. The water from a stream cannot be appropriated or diverted for supply or irrigation purposes by a single property holder without the consent of the other riparian owners, and without compensation to them.
38
CHAPTER II Appliances for Distributing Water
We have so far discussed only the various sources of potable water. We must now turn our attention to the mechanical means for making it available for use, which comprise appliances for lifting, storing, conveying, distributing, and purifying the water.
The location of the source of supply with refer- ence to the buildings and grounds decides generally the question whether a gravity supply is feasible or whether water must be pumped. The former is de- sirable because its operating expenses are almost noth- ing, but it is not always cheapest in first cost. Rather than have a very long line of conduit, it may be cheaper to pump water, particularly if wind or water power, costing nothing, can be used.
Machines for Pumping
When it becomes necessary to pump water, there are numerous machines from which to choose; only the more important ones will be considered. We may use pumps operated by manual labor, those run by ani-
39
Appliances for Water Distribution
mal power, pumping machinery using the power of the wind or that of faUing or running water; then there are hot-air, steam, and electric pumps, besides several forms of internal-combustion engines, such as gas, gasoline, and oil engines. Each has advantages in certain locations and under certain conditions.
Of appliances utilizing the forces of Nature, per- haps the simplest efficient machine is the hydraulic ram. While other machines for lifting water are composed of two parts, namely, a motor and a pump, the ram combines both in one apparatus. It is a self-acting pump of the impulse type, in which force is suddenly applied and discontinued, these periodical applications resulting in the lifting of water. Single-acting rams pump the water which operates them; double-acting rams utilize an impure supply to lift a pure supply from a different source.
The advantages of the ram are: it works con- tinuously, day and night, summer and winter, with but very little attendance; no lubrication is required, re- pairs are few, the first cost of installation is small. Frost protection, however, is essential. The disadvan- tages are that a ram can be used only where a large volume of water is available. The correct setting up is important, also the proper proportioning in size and length of drive and discharge pipes. The continual jarring tends to strain the pipes, joints, and valves; hence, heavy piping and fittings are necessary. A ram of the improved type raises water from twenty-
40
William Paul Gerhard
five to thirty feet for every foot of fall in the drive pipe, and its efficiency is from seventy to eighty per cent.
Running water is a most convenient and cheap power, which is often utilized in water wheels and turbines. These supply power to run a pump; the water to be raised may come from any source, and the pump may be placed at some distance from the water wheel. Where sufficient fall is available — at least three feet — the overshot wheel is used. In California and some other Western States an impulse water wheel is much used, which is especially adapted to high heads.
Windmills Used for Driving Pumps
The power of the wind applied to a windmill is much used for driving pumps. It is a long step for- ward from the ancient and picturesque Dutch form of windmill, consisting of only four arms with cloth sails, to the modern improved forms of wheels con- structed in wood and in iron, with a large number of impulse blades, and provided with devices regulating the speed, turning the wheel out of the wind during a gale, and stopping it automatically when the storage tank is filled. The useful power developed by wind- mills when pumping water in a moderate wind, say of sixteen miles an hour velocity, is not very high, ranging from one twenty-fifth horse-power for an eight and one-half foot wheel to one and one-half horse-
41
Appliances for Water Distribution
power for a twenty-five foot wheel. The claims of some makers of windmills as to the power developed should be accepted with caution.
The chief advantage is that, like a ram, the wind- mill may work night and day, with but slight atten- tion to lubrication, so long as the wind blows. But there are also drawbacks ; it requires very large storage tanks to provide for periods of calm; the wheel must be placed sufficiently exposed to receive the full wind force, either on a tower or on a high hill, and usually this is not the best place to find water. Besides, a windmill tower, at least the modern one, is not an ornamental feature in the landscape. It is expensive when built sufficiently strong to withstand severe win- ter gales. During the hot months of the year, when the farmer, the gardener, and the coachman require most water, the wind is apt to fail entirely for days in succession.
The Use of Engines
If water is not available^ and wind is considered too unreliable, pumping must be accomplished by using an engine which, no matter of what form or type, derives its energy from the combustion of fuel, be the same coal, wood, charcoal, petroleum or kerosene, gas, gaso- line, or naphtha. The use of such pumping engines implies a constant expense for fuel, operation, main- tenance, and repairs. In some modern forms of en- gines this expense is small, notably so in the oil engine,
42
William Paul Gerhard
and also in the gasoline engine ; hence these types have become favorites.
Advantages of Pumping Engines
An advantage common to all pumping engines is that they can be run at any time, not like the windmill, which does not operate in a light breeze, nor like the ram, which fails when the brook runs low. Domestic pumping engines are built as simple as possible, so that the gardener, a farm hand, or the domestic help may run them. Skill is not required to operate them, and they are constructed so as to be safe, provided ordinary intelligence is applied.
In using a fuel engine it is desirable, because of the attendance required, to take a machine of such capacity and size that the water supply required for two or three days may be pumped to the storage tank in a few hours.
Expansive Force of Heated Air Utilized
A favorite and extensively used type ctf domestic pump is the hot-air engine, in which the expansive force of heated air is used to do useful work. Among the types are simple and safe machines which do not easily get out of order. They are started by hand by giving the fly wheel one or more revolutions. If prop- erly taken care of they are durable and do not require expensive repairs.
43
Appliances for Water Distribution
Gas and Gasoline Engines
In gas engines power is derived from the explosion of a mixture of gas and air. Where a gas supply is available, such engines are very convenient, for, once started, they will run for hours without attention. They are economical in the consumption of gas, and give trouble only where the quality of gas varies.
Owing to the unavailability of gas on the farm and in country houses, two other forms of pumping engines have been devised which are becoming ex- ceedingly popular. One is the gasoline, the other is the oil engine. Both resemble the gas engine, but differ from it in using a liquid fuel which is volatilized by a sprayer. Gasoline engines are now brought to a high state of perfection.
Kerosene or Crude Oil as Fuel
In recent years, internal-combustion engines which use heavy kerosene or crude oil as fuel have been introduced. These have two palpable advantages: first, they are safer than gasoline engines ; second, they cost less to run, for crude oil and even refined kerosene are much cheaper than gasoline. Oil engines resemble the gas and gasoline engines, but they have larger cylinders, because the mean effective pressure evolved from the explosion is much less than that of the gaso- line engines.
44
William Paul Gerhard
Oil engines for pumping water are particularly suitable in regions where coal and wood cannot be obtained except at exorbitant cost. Usually, the engine is so built as to be adapted for other farm work. It shares this advantage with the gasoline engine. Oil engines are simple, reliable, almost automatic, compact, and reasonable in first cost and in cost of repairs. There are many forms of such engines in the market. To be successful from a commercial point of view, an oil engine should be so designed and built that any unskilled attendant can run, adjust, and clean it. The cost of operating them, at eight cents per gallon for kerosene, is only one cent per hour per horse-power; or one-half of this when ordinary crude oil is used. The only attention required when running is periodical lubrication and occasional replenishing of the oil reser- voir. The noise of the exhaust, common to all engines using an explosive force, can be largely done away with by using a muffler or a silencer. The smell of oil from the exhaust likewise forms an objection, but can be overcome by the use of an exhaust washer.
Steam and Electric Pumps
The well-known forms of steam-pumping engines need not be considered in detail, because high-pressure steam is not often available in country houses. Where electric current is brought to the building, or gen- erated for lighting purposes, water may be pumped
45
Appliances for Water Distribution
by an electric pump. Electric motors are easy and convenient to run, very clean, but so far not very economical. Electric pumps may be arranged so as to start and stop entirely automatically. Water may be pumped, where electricity forms the power, either by triplex plunger pumps or by rotary, screw, or cen- trifugal pumps.
Pumps Worked by Hand
Space forbids giving a description of the many simpler devices used for lifting water. In small farm- houses lift and force pumps worked by hand are now introduced, and the old-fashioned, moss-covered draw- bucket, which is neither convenient nor sanitary, is becoming a relic of past times.
Reservoirs and Storage Tanks
The water pumped is stored either in small ma- sonry or earth reservoirs, or else in storage tanks of either wood, iron, or steel, placed on a wood or steel tower. Wooden tanks are cheap but unsightly, re- quire frequent renewal of the paint, and give trouble by leaking, freezing, and corrosion of hoops. In re- cent years elevated tanks are supplanted by pressure tanks. Several such systems, differing but little from one another, are becoming quite well known. In these water is stored under suitable pressure in air-tight tanks, filled partly with water and partly with air.
46
William Paul Gerhard
A Simple Pressure System
One system consists of a circular, wrought-steel, closed tank, made air- and water-tight, a force pump for pumping water into the tank, and pipe connections. The tank is placed either horizontally or vertically in the basement or cellar, or else placed outdoors in the ground at a depth below freezing. Water is pumped into the bottom of the tank, whereby its air acquires sufficient pressure to force water to the upper floors.
This simple system has some marked advantages over the outside or the attic tank. In these, water gets warm in summer and freezes in winter. Vermin and dust get into the tank, and the water stagnates. In the pressure tank, water is kept aerated, cool, and clean.
Another pressure tank has an automatic valve, controlled by a float and connected with suction of pump. It prevents the tank from becoming water- logged by maintaining the correct amount of air inside.
'An Ideal System for a Country House
Still another system using pressure tanks is more complete than either of the others, comprising engine, pump, air compressor, a water tank, and also an air tank. It is best described by a recent example con- structed from plans and under the direction of the writer. The buildings supplied with water comprise the mansion, the stable, the cottage, and a dairy, and
47
Appliances for Water Distribution
48
William Paul Gerhard
the pumping station is placed near the shore of the lake from which the supply is taken. See Figs, i and 2.
The pump house is about 20 feet by 27 feet, and
Fig. 2.
PRESSURE-TANK PUMPING STATION. Interior view of pumping station of compressed air-tank system (see plan on opposite page) showing 3,000 gallon water tank, air tank of 150 pounds pressure and 10 horse-power gasoline engine.
contains a water-storage tank 6 feet in diameter and 13J feet long, of a capacity of 3,000 gallons; an air tank of same dimensions as the water tank, holding air under 150 pounds pressure; a 10 horse-power gasoline engine, direct-connected, by means of friction clutch,
49
Appliances for Water Distribution
with an air compressor and also with a triplex pump of 75 gallons capacity per minute.
The water in the tank is kept under 75 pounds pres- sure, and at the hydrant near the house, located about 100 feet above the pumping station, there is an avail- able pressure of 33 pounds. The last drop of water flows from the water tank under the full pressure of 75 pounds at the pumping station. The suction pipe into the lake is 4 inches and is provided with well strainers to prevent clogging. -f*
The cost of pumping water by this system is quite reasonable. The gasoline engine requires per horse- power per hour about \\ gallons of gasoline, and at sixteen cents per gallon this makes the cost for 1,000 gallons pumped about five cents. To this expense should, however, be added the cost of lubricating oil, repairs, amount for depreciation, and the small cost for labor in running the engine.
Water pipes forming a distribution system should always be chosen generous in diameter, in order to avoid undue loss of pressure by friction. Where fire hydrants are provided, the size of the water main should not be below four inches. All branches should be controlled by shut-offs, for which the full- way gate valves are used in preference to globe valves. Pipe-line material is usually galvanized, screw-jointed wrought iron for sizes up to four inches.
In conclusion;, a word about water purification. Where the quality of the water supply is not above
50
William Paul Gerhard
suspicion it may be improved by filtration. A filter should never be installed without the advice of a quali- fied expert, for there are numerous worthless devices and few really efficient ones. Where a filter is not available, the water used for drinking should be boiled or sterilized if there is the slightest doubt as to its wholesomeness.
51
CHAPTER III Purifying Water by Copper Sulphate
From the standpoint of the health of the com- munity, the most vital problem is to get pure water. Almost equally important, when comfort and peace of mind is considered, is the procuring of sweet water. The wise owner of a country home looks to the water supply upon which his family is dependent. The care- ful farmer is particular about the water his stock, as well as his family, must drink. But careless persons constitute the large majority. Most people in the city and in the country pay no attention to their drinking water so long as it " tastes all right."
Clear Water Often Dangerous
Some years ago the inhabitants of Ithaca, N. Y., furnished a pitiful example of this foolhardy spirit. For a year previous to the breaking out of the typhoid epidemic, the public was warned, through the local and the metropolitan press, of the dangerous condition of Ithaca's water supply. Professors of Cornell Col- lege joined in these warnings. But the people gave no heed, probably because the water was clear and its taste sweet and agreeable. As was the case in this instance,
52
Use of Copper Sulphate
bacteria are tolerated indefinitely, and it is only an alarming increase in the death rate that makes people careful. Then they begin to boil the water — when it is too late for some of them.
Bad-Tasting Water not '^Always Poisonous
But let the taste become bad and the odor repulsive, and a scare is easily started. " There must be dead things in the water, or it wouldn't taste so horrible," is the common verdict. Some newspaper seizes upon the trouble and makes of it a sensation. The ubiquitous reporter writes of one of '' the animals " that it " looks like a wagon wheel and tastes like a fish." With such a remarkable organism contaminating one's drink no wonder there is fear of some dread disease. The water is believed to be full of " germs " ; whereas the pol- lution is entirely due to the presence of alg^ — never poisonous to mankind, in some cases acting as purify- ing agents, but at certain seasons of the year impart- ing a taste and odor to the water that cannot be tol- erated.
Algae — ^what are they? They are aquatic plants. Algae are not to be confounded with the water vegeta- tion common to the eye and passing by the term weeds. Such plants include eelgrass, pickerel weed, water plantain, and " duckmeat " — all of which have roots and produce flowers. This vegetation does not lend a bad odor or taste to the water. In itself it is harm-
53
Purifying the Water Supply
less, although it sometimes affords a refuge for or- ganisms of a virulent type.
But when the aquatic vegetation of the flowering variety is eliminated from consideration, there still re- mains a group of water plants called algae. They comprise one-fifth of the known flowerless plants. They are the ancestors of the entire vegetable kingdom. Those whose habitat is the sea number the largest plants known in nature. Certain forms found in the Pacific are supposed to be 800 feet in length; others are reported to be 1,500 feet long. The marine variety are familiar as the brown kelps and the wracks, which are very common along our Northern coast.
Plants Which Pollute Drinking Water
The fresh-water algae are usually grass green in color. This green variety is often seen as a spongy coating to the surface of stagnant pools, which goes by the name of " frog spawn " or " pond scum." One of this description, Spirogyra, has done thousands of dollars' worth of damage by smothering the life out of young water-cress plants in artificial beds constructed for winter propagation. When the cress is cut the plants are necessarily left in a weakened condition, and the algae form a thick mat over the surface of the water, thus preventing the growth of the cress plants and oftentimes killing them. The absolute necessity of exterminating these algae led to the perfection of the copper-purification process.
54
Use of Copper Sulphate
It is, however, a variety of algae not easily detected that contaminates the water. So long as they are in a live, healthy condition they benefit drinking water by purifying it. Indeed, some scientists have attributed the so-called self -purification of a stream entirely to the activities of these plants. Of such, one form, Chlamydomonas, is bright grass green in appearance. But the largest group — the plants which have the worst reputation as polluters of drinking water — are popularly known as the " blue-green algae " {Schis- ophycece). The common name tells the color of these plants, although there are exceptions in this respect, some of them showing shades of yellow, brown, olive, chocolate, and purplish red. This variety of algae flourishes in the summer months, since a relatively high temperature and shallow stagnant water favor its germination. If the pond begins to dry up, the death of the organisms takes place, and the result is a most disagreeable, persistent odor which renders the water unfit for drinking purposes. This result is chemically due to the breaking down of highly organized com- pounds of sulphur and phosphorus in the presence of the large amount of nitrogen contained in these plants. Decomposition is not necessary for some of the blue greens to give off a bad odor, however. A number of them, on account of their oil-content, produce an odor when in a healthy condition that is sometimes likened to raw green corn or to nasturtiums, but usually it cannot be so pleasantly described.
55
Purifying the Water Supply
The Department of Agriculture has been able to solve the problem of exterminating algae from water supplies.^ The department has done more; for it has succeeded in perfecting a method by which a reservoir contaminated with typhoid or other pathogenic bac- teria can be purified. The work was begun with an inquiry into the extent of the trouble from algal pol- lution. Letters were addressed to some five hundred engineers and superintendents of water companies scat- tered all over the United States. The replies, which came from almost every State in the Union, were bur- dened with one complaint — " Algse are our worst pest " ; and with one prayer — " Come over into Mace- donia, and help us."
A Cheap and Available Remedy for Algce
Convinced of the need of earnest work, extensive laboratory experiments were inaugurated. The prob- lem presented was this: the remedy must not only be readily available, but it must be cheap, that advan- tage may be taken of it by the poorest communities, as well as by those owning large reservoirs. Above all, the remedy must be absolutely harmless to man; the poison used to exterminate algae must not in any way affect the water drinkers. A large number of sub-
^ For published reports of the work, see Bulletins 64 and 76, Bureau of Plant Industry, U. S. Department of Agriculture; reports prepared by Dr. George T. Moore and his assistant, Mr. Karl F. Kellerman.
56
Use of Copper Sulphate
stances were used in the experiments before the final decision rested with copper sulphate. This salt is very poisonous to algae. On the other hand, copper in solu- tion just strong enough to destroy algal growth could not possibly injure man; in fact, the temporary pres- ence of such a small amount of copper in drinking water could not be detected.
A Practical Demonstration
The results in the laboratory being successful, the next step was to make a practical demonstration of the value of the method. This was first done in the fall of 1 90 1. At Ben, Va., water cress is grown in large quantities during the winter, when it is a valuable market crop. Dams are constructed across a stream in such a manner as to enable the maintenance of a water level not too high for the growth of plants ; when a freeze is threatened the plants can be flooded. In the cress beds selected for the experiments the water is obtained from a thermal spring whose temperature throughout the year is about 70° F. This temperature is particularly favorable to the growth of " frog spawn." After the cress was cut for market, the algae frequently developed so rapidly as to smother the life out of the weakened plants. When this occurred, the practice was to rake out both water cress and algae and reset the entire bed. This was not only expensive; half the time it failed to exterminate the pest. It was,
57
Purifying the Water Supply
therefore, most desirable to devise a method of ridding the bed of algal growth without injuring the cress.
The Copper-sulphate Method Tested
Here the copper-sulphate method was put to a practical test. At the outset a strong solution was sprayed on the algae which coated the surface of the pond. This only killed the algal growth with which the particles of copper came in contact and left the main body of algae unaffected. Then trial was made of dissolving the copper directly in the water, and the result was most satisfactory. The solution used was that of I part of copper to 50,000,000 parts of water.
Growers need have no trouble in the future. They need have no fear of employing the method, as the copper solution required for killing the algae could not possibly injure water cress, provided ordinary care is used in the work. As to the frequency of treatment required, one or two applications a year will generally be found sufficient, as this letter, received from the manager of the Virginia company, goes to show :
" The * moss ' has given me no trouble at all this winter; in fact, I have for six months had to resort to the copper sulphate only once. . . . All the condi- tions were favorable last fall and early winter for a riot of * moss,' but it did not appear at all until just a few days ago, and then yielded to treatment much more readily than it did when I first began to use the
58
Use of Copper Sulphate
copper. '* This letter was written over three years after Dr. Moore made his experiment in these cress beds.
Satisfied with the results attained in exterminating algal growth in water-cress beds, attention was next given to reservoirs. Some fifty water supplies were treated during the summer of 1904, and in every case success attended the copper cure. In one respect the results were surprising. It was found that in practice the copper-sulphate method worked better than in theoretic experimentation; results in large reservoirs were more pronounced than in the laboratory. In fact, it developed that the solution necessary to kill algae in the laboratory must contain from five to twenty times as much copper as that contained in a solution which will exterminate algal growth in its natural habitat. This is not easily explained, if it can be explained at all. The best reason advanced is that only the most resistant organisms stand transplanting to an artificial environment. But, after all, the important point is that the new method works better in practice than was expected.
A Prescription for the Copper Cure
Thus the department is able to announce that the process is no longer in the experimental stage, and also to say what conditions must be known in determining the proper quantity of copper sulphate for destroying algae, together with a prescription for the copper cure.
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Purifying the Water Supply
Here it is, for the benefit of careful persons who will use the method with proper intelligence : " The importance of knowing the temperature of the con- taminated water is second only to the necessity of knowing the organism present. With increase of tem- perature the toxicity of a given dilution increases, and vice versa. Assuming that 59° F. is the average tem- perature of reservoirs during the seasons when treat- ment is demanded, the quantity of copper should be increased or decreased approximately 2.5 per cent for each degree below^ or above 59° F.
" Similar scales should be arranged for the organic content and the temporary hardness of the water. With the limited data at hand it is impracticable to determine these figures, but an increase of 2 per cent in the quantity of copper for each part per 100,000 of organic matter and an increase of 0.5 to 5 per cent in the proportion of copper for each part per 100,000 of temporary hardness will possibly be found correct. The proper variation in the increase due to hardness will depend upon the amount of dissolved carbon dioxide; if very small, 5 per cent increase is desirable; if large, 0.5 per cent is sufficient."
The information in this prescription is to be used in connection with a table ^ published by the Depart- ment of Agriculture. This table gives the number of parts of water to one part of copper sulphate necessary to kill the various forms of algae which are listed. The
^ See Bulletin No. 76, supra. 60
Use of Copper Sulphate
formulae vary from i part of copper to 100,000 parts of water, necessary to destroy the most resistant and very rare forms (three of these are Hsted), to i part of copper in 25,000,000 parts of water, which is a sufficiently strong solution to exterminate Spire gyra, the cress-bed pest. By far the majority of forms do not require a solution stronger than that of i part of copper to 1,000,000 parts of water.
What the Agricultural Department is Doing
It is true that the department is not now holding out, directly, a helping hand to the owner of a country place, or to the farmer, in this campaign of purifying drinking water. In the first place, the greatest good of the greatest number demands that large reservoirs, which supply a great number of people with drinking water, ought to be considered first. Such supplies, moreover, are most frequently contaminated. Where fifty reservoirs were treated last summer, ten times that number will be " cured " this summer. It will be readily seen, therefore, that in conducting such a large number of experiments — considering preliminary re- ports, prescribing for treatment, and keeping proper account of results — the department, with a limited force and limited facilities, has its hands more than full.
More important still, there is an absolute need of the services of some expert on the ground. While an
61
Purifying the Water Supply
algologist is a functionary not generally employed by water companies — in fact, a man trained in the physi- ology of algae is difficult to find — nevertheless, it is highly important, as the department views it, to have the cooperation of an expert versed to some extent in the biological examination of drinking water. In other words, the copper cure is not a " patent medi- cine," with printed directions which any person could follow. Intelligence and care are absolutely essential in the use of this treatment. Furthermore, each case must be treated as a distinct and separate case, as a physician would treat a patient.
^Actual Purification Simple
Suppose, however, an owner of a country place, which is dependent upon a fresh-water pond for its water supply, finds that his drinking water is con- taminated, that the taste and odor are such as to ren- der the water unfit for use. There is no reason why he should not treat the supply, provided he is properly careful. When the nature of the polluting organism is definitely determined and the average temperature of the water observed, then the necessary formula can be decided upon. First, of course, the pond must be plotted, the depth found, and the capacity computed, the department will willingly furnish data for this purpose, together with blanks upon which to submit details as to contaminating organisms and water tem-
62
Use of Copper Sulphate
perature, to any applicant. Once the proper solution is determined upon, the actual work of purification is most simple. In the following directions the de- partment outlines the most practicable method of in- troducing the copper sulphate into a water supply :
Directions for the Copper Cure
" Place the required number of pounds of copper sulphate in a coarse bag — gunny sack or some equally loose mesh^— and, attaching this to the stem of a row- boat near the surface of the water, row slowly back and forth over the reservoir, on each trip keeping the boat within ten to twenty feet of the previous path. In this manner about a hundred pounds of copper sul- phate can be distributed in one hour. By increasing the number of boats, and, in the case of deep reser- voirs, hanging two or three bags to each boat, the treatment of even a large reservoir may be accom- plished in from four to six hours. It is necessary, of course, to reduce as much as possible the time re- quired for applying the copper, so that for immense supplies, with a capacity of several billion gallons, it would probably be desirable to use a launch, carrying long projecting spars to which could be attached bags containing several hundred pounds of copper sulphate.
'' The substitution of wire netting for the gunny- sack bag allows a more rapid solution of the sulphate, and the time required for the introduction of the salt
63
Purifying the Water Supply
may thus be considerably reduced. It is best to select as warm a day for treatment as circumstances will permit."
Cost of the Treatment
Not difficult, one would say. No — when the proper solution is determined; to reach that determination is the difficulty. That the method can be tried " at home "is proved by the results obtained by the owner of a country home in the vicinity of New York. Tired of consulting engineers, who looked at his water sup- ply, informed him that they could do nothing, and then charged him a big fee (to one he paid $250), this owner resorted to the copper-sulphate treatment. The cure cost the man just $2 — but let his letter to the department tell the story :
" My place in the country is located at Water Mill, in the township of Southampton, in Long Island. I purchased it in April, 1902, and was largely influenced in selecting this piece of land by the beauty of a pond which bounds it on the east. This little body of water covers about two acres, is fed by numerous springs, and discharges into Mecox Bay, the southern boundary of the land. When I bought the place the pond was filled with clear water. About the middle of the fol- lowing June algae began to show, and in August the surface was almost entirely covered by the growth. The odor was offensive, and myriads of small insects hovered over the masses of algae much of the time.
64
Use of Copper Sulphate
I consulted two engineers interested in the storage of water, and they told me that nothing could be done. The condition was so objectionable that I planned to plant a thick hedge of willows along the bank to shut off the view of the pond from the house. ... I ex- amined the pond on June 15th and found large masses of algae covering an area several hundred feet in length and from twenty to forty feet in width. No microscopical examination was made of the growth, but I was informed that it seemed to be largely com- posed of filaments of Spirogyra and other Confervce. On June i8th the treatment was begun. ... In one week the growth had sunk and the pond was clear water. I examined the pond September 15th and found it still clear.
" The use of the sulphate of copper converted an offensive insect-breeding pond into a body of beauti- fully clear water. The pond was full of fish, but the copper did not seem to harm them."
Effect of Copper Sulphate on Fish
Native trout were not injured when the large reser- voir at Cambridge, N. Y., was purified by the copper treatment. A slightly different result, in this respect, was reported from Elmira, N. Y., however. Part of the report is as follows :
" The effect of the copper-sulphate treatment on the different animal life was as follows : numerous ' polly-
65
Purifying the Water Supply
wogs ' killed, but no frogs; numerous small (less than two inches long) black bass and two large ones (eight inches long) killed; about ten large 'bullheads' were killed, but no small ones; numerous small (less than two inches long) ' sunfish ' were killed, but no large ones.
" The wind brought the dead fish to the comers of the reservoir, and it was very little trouble to remove them. No dead fish were seen twenty- four hours after completion of the treatment.*'
The injury done by copper sulphate to fish is a more serious matter than was at first supposed. Brook trout are, apparently, the least resistant to the salt. A Massachusetts trout pond stocked with eight-inch trout lost forty per cent as a result of the introduction of a strong solution of copper sulphate. The Bureau of Fisheries is working in conjunction with the Division of Plant Physiology in this matter, and it is hoped to secure reliable information. In the meantime, owners of ponds stocked with game fish would do well to take great care before resorting to the copper cure for algae — that is, if they hesitate to lose a part of the fish.
Water May he Drunk During Treatment
When a pond or reservoir is treated with the proper amount of copper sulphate to remove algse — except in the case of the few very resistant forms requiring a stronger solution than i part of copper to 1,000,000
66
Use of Copper Sulphate
parts of water — there is no need of discontinuing the use of the water supply during treatment; the water may be drunk with impunity. But when water known to be polluted with pathogenic bacteria is sterilized by means of copper sulphate in strong solution, it is just as well to discontinue the use of the water for drinking purposes for not more than twenty-four hours. Even then, this is an overcareful precaution rather than a necessity.
Experiments conducted with great care and thor- oughness demonstrate that at room temperature, which is near the temperature of a reservoir in summer, a solution of I part of copper to 100,000 parts of water will destroy typhoid bacteria in from three to five hours. Similar experiments have proved that a copper solution of like strength is fatal to cholera germs in three hours, provided the temperature is above 20° F. As was the case with algse, bacteria were found to be much more sensitive to copper when pol- luting water than when grown in artificial media.
The Use of Copper Tanks
The toxic effect of metallic copper upon typhoid bacteria in water gives some hints as to prevention of the disease by the use of copper tanks. This should not altogether take the place of the boiling of the water; it is useful in keeping it free from contamina- tion, although water allowed to stand in copper re-
67
Purifying the Water Supply
ceptacles for a period of from twenty- four to forty- eight hours at room temperature would be effectively sterilized, no matter what its contamination and no matter how much matter it held in suspension. But in order to insure such results the copper must be kept thoroughly clean. This polishing is not, as was popu- larly supposed, to protect the consumer from " copper poisoning," but to prevent the metal from becoming so coated with foreign substances that there is no con- tact of the copper with the water, hence no antiseptic quality.
Dr. Henry Kreamer, of Philadelphia, proved that within four hours typhoid germs were completely de- stroyed by the introduction into the polluted water of copper foil.
*' Granting the efficiency of the boiling of w^ater for domestic purposes, I believe that the copper-treated water is more natural and more healthful. . . . The intestinal bacteria, like colon and typhoid, are com- pletely destroyed by placing clean copper foil in the water containing them.
" Pending the introduction of the copper treatment of water on a large scale, the householder may avail himself of a method for the purification of drinking water by the use of strips of copper foil about three and one-half inches square to each quart of water, this being allowed to stand overnight, or from six to eight hours at the ordinary temperature, and then the water drawn off or the copper foil removed."
6^
Use of Copper Sulphate
Although a splendid antiseptic, copper in weak solution is not harmful, no more so than the old copper utensils used by our forefathers were harmful. Undoubtedly they were of benefit, and the use of them prevented the growth of typhoid and other bacteria. People of to-day might well go back to copper re- ceptacles for drinking water.
69
CHAPTER IV Ridding Stagnant Water of Mosquitoes
Because of the serious and often fatal injury it inflicts on man, the most dangerous animal known is the mosquito. Compared with the evil done by the insect pest, the cobra's death toll is small. This venomous serpent is found only in hot countries, particularly in India, while mosquitoes know no fa- vorite land or clime — unless it be Jersey. Arctic explorers complain of them. In Alaska, it is recorded by a scientist that " mosquitoes existed in countless millions, driving us to the verge of suicide or in- sanity." A traveler on the north shore of Lake Su- perior, when the snow was several feet deep, and the ice on the lake five feet in thickness, relates that " mos- quitoes appeared in swarms, literally blackening the banks of snow in sheltered places."
Mosquitoes Responsible for Yellow Fever
In the temperate zone this evil-breeding insect was, until recent years^ considered more in the light of an exasperating pest. It is now known, however, that
70
Best Methods to Employ
malaria is due entirely to the bites of mosquitoes. But it is in the tropical countries that their deadliest work is done. There, it has been proved beyond question, the mosquitoes are responsible for the carriage of yellow fever. If, in a yellow-fever ridden region, one were to live entirely in an inclosure, carefully protected with proper screens — as certain entomolo- gists did — there practically would be no danger from the dread disease, even if all other precautions were neglected.
Effect of a Mosquito Bite
The crime committed by the mosquito against its innocent victim, man, is more in the nature of man- slaughter than of murder, according to the authorities. There is no premeditated malice. " A mosquito bites primarily to obtain food," says a leading entomologist ; " there is neither malice nor venom in the intent, what- ever there may be in the act.'^ There isn't great com- fort in the intelligence conveyed by the scientist, nor in his further observation :
" Theoretically, there would seem to be no reason why there should be any pain from the introduction of the minute lancets of the insects, and the small amount of bloodletting is usually a benefit rather than otherwise. Unfortunately, however, in its normal condition the human blood is too much inclined to clot to be taken unchanged into the mosquito stomach;
71
Ridding Stagnant Water of Mosquitoes
hence, when the insect bites, a minute droplet of poison is introduced, whose function it is to thin out the fluid and make it more suitable for mosquito digestion. It is this poison that sets up the inflammation and produces the irritation or swelling. . . . The pain is caused entirely by the action of the poison in break- ing up the blood, and, as the first act of a biting mosquito is to introduce the poison into the wound, the pain and inflammation will be the same, whether the insect gets its meal or not. In fact, it has been said that if a mosquito be allowed to suck its fill and then fly, the bite will not itch, and there is just a basis of justification for this."
To make a scientific inquiry into the habits of the mosquito, and to do it patiently, one should be far from the maddening swarms, or at least effectively screened in. Then it would be possible to believe the statement of the Government's entomologist that not " one mosquito in a million " ever gets the opportunity to taste the blood of a warm-blooded animal. As proof of this there are, in this country, great tracts of marshy land never frequented by warm-blooded animals, and in which mosquitoes are breeding in countless num- bers. The point is emphasized by the prevalence of mosquitoes in the arctic circle and other uninhabited regions.
If this gory insect does not live by blood alone, how is it nourished ? Female mosquitoes are by nature vegetarians ; they are plant feeders. Why they should
72
Best Methods to Employ
draw blood at all is a question which remains un- solved by entomologists — as well as by the suffering victims. The females have been observed sucking the nectar from flowers; obtaining nutriment from boiled potatoes, even from watermelon rinds, from which they extract the juice. As regards the blood habit, the male mosquito is a " teetotaler." Just how this male insect lives, scientists have not determined. He may not take nourishment at all. At any rate, the mouth parts of the male are so different from those of the female that it is probable his food is obtained differently. The male is often seen sipping at drops of water, and a taste for molasses is ascribed to the male mosquito by one authority.
Presence of Mosquitoes Depends Upon Winds
A common remark heard along the Jersey shore, also on Long Island, is this : " When we have a sea breeze we are not troubled with mosquitoes, but when there comes a land breeze they are a pest." While this observation is true, the reasons therefore entertained by the unscientific mind are erroneous. The matter of the absence or abundance of mosquitoes in varying winds is closely related to the inquiry which entomologists have made: how far will mosquitoes fly? Says one investigator :
" The migration of mosquitoes has been the source of much misapprehension on the part of the public.
73
Ridding Stagnant Water of Mosquitoes
The idea prevalent at our seaside resorts that a land breeze brings swarms of mosquitoes from far inland is based on the supposition that these insects are capable of long-sustained flight, and a certain amount of battling against the wind. This is an error. Mos- quitoes are frail of wing; a light puff of breath will illustrate this by hurling the helpless creature away, and it will not venture on the wing again for some time after finding a safe harbor. The prevalence of mosquitoes during a land breeze is easily explained. It is usually only during the lulls in the wind that Culex can fly. Generally on our coast a sea breeze means a stiff breeze, and during these mosquitoes will be found hovering on the leeward side of houses, sand dunes, and thick foliage. . . . While the strong breezes last, they will stick closely to these friendly shelters, though a cluster of houses may be but a few rods off, filled with unsuspecting mortals who imagine their tormentors are far inland over the salt meadows. But if the wind dies down, as it usually does when veering, out come swarms upon swarms of females intent upon satisfying their depraved taste for blood. This explains why they appear on the field of action almost immediately after the cessation of the strong breeze; on the supposition that they were blown inland, this sudden reappearance would be un- accountable."
A sultry, rainy period of midsummer is commonly referred to as " good mosquito weather." The ac-
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Best Methods to Employ
cepted idea is that mosquitoes are much more abundant at such times. This is true, and the explanation is simple. Mosquito larvae, or wrigglers, as they are termed, require water for their development. A heavy- shower leaves standing water, which, when the air is full of moisture, evaporates slowly. Then, too, the heat favors the growth of the microorganisms on which the larvae feed; wrigglers found in the water forty- eight hours after their formation will have plenty of food, and adult mosquitoes will appear six to eight days after the eggs are laid. Clear weather, with quick evaporation, interferes with the development of the wrigglers, so that a season with plenty of rain, but with sunshiny, drying weather intervening, is not " good mosquito weather."
Destroy the Larvce
Inasmuch as a generation of mosquitoes appear to torment man within ten days, at the longest, after the eggs are laid; as a batch laid by a female mosquito contains from two hundred to four hundred eggs ; as from each ^gg may issue a larva or wriggler which in six days will be an adult mosquito on the wing — it is to the destruction of the larvae that attention should be directed. The larva is a slender organism, white or gray in color, comprising eight segments. The last of these parts is in the form of a tube, through which the wriggler breathes. Although its habitat is the
75
Ridding Stagnant Water of Mosquitoes
water, it must come to the surface to breathe, there- fore its natural position is head down and tail, or respiratory tube, up. Now, if oil is spread on the surface of a pool inhabited by mosquito larvae, the wrigglers are denied access to the air which they must have. Therefore, they drown, just as any other air- breathing animal would drown under similar circum- stances.
Best Preventive Measures
As to the best methods to employ in ridding a country place, or any other region, of mosquitoes, the directions furnished by Dr. L. O. Howard, the Govern- ment entomologist, who has been a careful student of the problem since 1867, are of great value :
'' Altogether,^ the most satisfactory ways of fight- ing mosquitoes are those which result in the destruction of the larvae or the abolition of their breeding places. In not every locality are these measures feasible, but in many places there is absolutely no necessity for the mosquito annoyance. The three main preventive measures are the draining of breeding places, the in- troduction of small fish into fishless breeding places, and the treatment of such pools with kerosene. These are three alternatives, any one of which will be effi- cacious and any one of which may be used where there are reasons against the trial of the others.
* See Bulletin No. 25, U. S. Department of Agriculture, Division of Entomology.
76
Best Methods to Employ
Quantity of Kerosene to he Used
" The quantity of kerosene to be practically used, as shown by the writer's experiments, is approximately one ounce to fifteen square feet of water surface, and ordinarily the application need not be renewed for one month. . . . The writer is now advising the use of the grade known as lubricating oil, as the result of the extensive experiments made on Staten Island. It is much more persistent than the ordinary illuminating oils. . . . On ponds of any size the quickest and most perfect method of forming a film of kerosene will be to spray the oil over the surface of the water. . . . It is not, however, the great sea marshes along the coast, where mosquitoes breed in countless numbers, which we can expect to treat by this method, but the inland places, where the mosquito supply is derived from comparatively small swamps and circumscribed pools. In most localities people endure the torment or direct their remedies against the adult insect only, without the slightest attempt to investigate the source of the supply, when the very first step should be the undertaking of such an investigation.
" The remedy which depends upon draining breed- ing places needs no extended discussion. Naturally the draining off of the water of pools will prevent mos- quitoes from breeding there, and the possibility of such draining and the means by which it may be done will vary with each individual case. The writer is in-
77
Ridding Stagnant Water of Mosquitoes
formed that an elaborate bit of work which has been done at Virginia Beach bears on this method. Behind the hotels at this place, the hotels themselves fronting upon the beach, was a large fresh-water lake, which, with its adjoining swamps, was a source of mosquito supply, and it was further feared that it made the neighborhood malarious. Two canals were cut from the lake to the ocean, and by means of machinery the water of the lake was changed from a body of fresh to a body of salt water. Water that is somewhat brackish will support mosquitoes, but water that is purely salt will destroy them.
Employing Fish to Destroy LarvcB
"The introduction of fish into fishless breeding places is another matter. It may be undesirable to treat certain breeding places with kerosene, as, for instance, water which is intended for drinking, al- though this has been done without harm in tanks where, as is customary, the drinking supply is drawn from the bottom of the tank. The value of most small fishes for the purpose of destroying mosquito larvae was well indicated by an experience described to us by Mr. C. H. Russell, of Bridgeport, Conn. In this case a very high tide broke away a dike and flooded the salt meadows of Stratford, a small town a few miles from Bridgeport. The receding tide left two small lakes, nearly side by side and of the same size.
78
Best Methods to Employ
In one lake the tide left a dozen or more small fishes, while the other was Ashless. An examination by Mr. Russell in the summer of 1891 showed that while the Ashless lake contained tens of thousands of mosquito larvae, that containing the fish had no larvae. The use of carp for this purpose has been demonstrated, but most small fish will answer as well. The writer knows of none that will be better than either of the common little sticklebacks {G aster est ens aculeatus or Pygos- teiis pungitius) ."
Is mosquito fighting a success ? This question is an all-important one, not only to the summer resident, but also to cities and towns contiguous to salt-water marshes, or to swampy lands, well suited for mosquito breeding. The answer is this : Mosquito control is possible; actual extermination impossible with an in- sect that develops so rapidly. The " Jersey mosquito," the unscientific name popularly given to an insect of huge size and ravenous appetite, has become famous. As a matter of fact^ the species of mosquitoes found in New Jersey are no more rare or varied than those found on Staten Island or on Long Island. But until very recently the region lying between Jersey City and Newark has been particularly favorable to the de- velopment of mosquito larvae. It has been announced in the press that mosquitoes have been driven out of the Newark meadows. This is an exaggeration, of course, but the work accomplished there is remarkable, and other infected regions may take heart from the
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Ridding Stagnant Water of Mosquitoes
marked success which has attended the efforts of Dr. John B. Smith, Entomologist of the New Jersey State Agricultural Experiment Station.
Remarkable Work Accomplished
The salt marsh lying within the limits of the city of Newark covers an area of about 3,500 acres. It extends from a point on the Passaic River to the mouth of Bound Creek, where it empties into Newark Bay. Its length is about eight miles and it has an extreme width of three miles. The Newark marsh problem was a very complex one. The meadows are cut into many sections by the several traversing railroads and by creeks; this materially influences the drainage. The Peddie Street sewer crosses the marsh in a straight line of about three miles from the city to the bay. This sewer is twenty feet wide, and its banks are from three to four feet above the marsh land.
An experiment with machine ditching was made in 1903. The worst parts of the marsh were selected, and about 40,000 feet of ditches were cut. These ditches were six inches wide, two feet deep, and the drainage was perfect from the outset. The section of meadow thus drained became so dry in consequence that the grass growing there can now be cut by a machine in summer, whereas formerly the hay could be mown only in winter. The work was so successful that the Newark Common Council appropriated $5,000
80
Best Methods to Employ
to complete the mosquito drainage of the marsh. Of the results obtained up to this spring, Dr. Smith says :
" This Newark marsh problem was an unusual one, and one that would not be likely to recur in the same way at any other point along the coast. Never- theless, of the entire 3,500 acres of marsh, not 100 acres remain on which there is any breeding what- ever, and that is dangerous only in a few places and under certain abnormal conditions. Including old ditches cleaned out, about 360,000 running feet of ditches have been dug on the Newark marshes, partly by machine and partly by hand, and if the work is not entirely successful, that is due to the defects which were not included in the drainage scheme. It is a safe prediction, I think, that Newark will have no early brood of mosquitoes in 1905, comparable with the in- vasions of 1903 and 1904."
This prophecy has proved true.
The Campaign on Long Island
The wealthy summer residents along the north shore of Long Island, keenly alive to the necessity of driving mosquitoes from the region where they spend so much of their time, have attacked the problem in a scientific, as well as an energetic way. The North Shore Improvement Association intrusted the work to Henry Clay Weeks, a sanitary engineer, with whom was associated, as entomologist, Prof. Charles B.
81
Ridding Stagnant Water of Mosquitoes
Davenport, Professor of Entomology at the University of Chicago and head of the Cold Spring Biological Laboratory; also F. E. Lutz, an instructor in biology at the University of Chicago. Prof. N. S. Shaler, of Harvard University, the most eminent authority in the country on marine marshes, was retained to make a special examination of the salt marshes with a view to recommending the best means of eliminating what were the most prolific breeding grounds of mosqui- toes. A detailed examination of the entire territory was made. Practically every breeding place of mos- quitoes, including the smaller pools and streams, and even the various artificial receptacles of water, were located and reported on. Mr. Weeks, with his as- sistant, then examined each body of water in which mosquito larvae had been found, with a view to devising the best means of preventing the further breeding of mosquitoes in these plague spots. Finally, a report was prepared, together with a map on which was located every natural breeding place.
Investigations in Connecticut
Important investigations have been made in Connecticut by the Agricultural Experiment Station, under the direction of W. E. Britton and Henry L. Viereck, and the results have been most encouraging. Dr. Howard, in his directions for fighting mosquitoes, acknowledges his indebtedness to the very successful
2,2
Best Methods to Employ
experiments carried on at Staten Island. Maryland is aroused to the point of action. Dr. Howard A. Kelley, of Johns Hopkins University, is to cooperate with Thomas B. Symons, the State entomologist, in carrying the war to the shores of Chesapeake Bay. " Home talent," moreover, can accomplish much. To fight intelligently, let it not be forgotten that the battle should be directed against the larvae. These wrigglers are bred for aquatic life ; therefore, it is to all standing water that attention should be directed. Mosquito larvae will not breed in large ponds, or in open, per- manent pools, except at the edges, because the water is ruffled by the wind. Any pool can be rendered free from wrigglers by cleaning up the edges and stocking with fish. Every fountain or artificial water basin ought to be so stocked, if it is only with goldfish. The house owner should not overlook any pond, how- ever small, or a puddle of water, a ditch, or any depression which retains water. A half-filled pail, a watering trough, even a tin receptacle will likely be populated with mosquito larvae. Water barrels are favorite haunts for wrigglers.
A Simple Household Remedy
There are those, however, who will obstinately conduct their campaign against the adult mosquito. If energetic, such persons will search the house with a kerosene cup attached to a stick; when this is held
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Ridding Stagnant Water of Mosquitoes
under resting mosquitoes the insects fall into the cup and are destroyed. Those possessed of less energy daub their faces and hands with camphor, or with the oil of pennyroyal, and bid defiance to the pests. With others it is, Slap! slap! — with irritation mental as well as physical; for the latter, entomologists recom- mend household ammonia.
Part II
PURE FOOD FOR THE HOUSEKEEPER
BY S. JOSEPHINE BAKER
CHAPTER I How to Detect Food Adulteration
Adulteration when applied to foodstuffs is a broad, general term, and covers all classes of misrepre- sentation, substitution, deterioration, or addition of foreign substances; adulteration may be either inten- tional or accidental, but the housekeeper should be prepared to recognize it and so protect herself and her household.
Food is considered adulterated when it can be classified under any of the following headings :
DEFINITIONS OF ADULTERATION._(i) If any substance has been mixed or packed with it so as to reduce or lower or injuriously affect its quality or strength.
(2) If any inferior substance has been substituted for it, wholly or in part.
(3) If any valuable constituent has been wholly or in part abstracted from it.
(4) If it consists wholly or in part of diseased or decomposed or putrid or rotten animal or vegetable substance, or any portion of an animal unfit for food, whether manufactured or not, or if it is the product
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Adulteration of Food
of a diseased animal or one who has died otherwise than by slaughter.
(5) If it be colored or coated or polished or pow- dered, whereby damage is concealed or it is made to appear better than it really is.
(6) If it contains any added poisonous ingredient or any ingredient which may render such article in- jurious to health; or if it contains any antiseptic or preservative not evident or not known to the purchaser or consumer.
FOOD LAWS.— There is now in effect in the United States a rigid law against the offering for sale of any article intended for human consumption which is adulterated in any way, without the fact and nature of such adulteration being plainly stated on a label attached to the package containing the article. This law, however, applies only to articles of this nature which originate, or are produced, in one State and offered for sale in another. The purchaser is, there- fore, in a great degree protected, but many foodstuffs or manufactured articles may have their origin within the State wherein they are sold, and in this case the only safeguards are those afforded by the laws of the State, city, or town immediately concerned. If these restraining laws do not exist or if they are not en- forced the housekeeper must rely upon her own efforts to protect her family from adulterated food.
PERMISSIBLE ADULTERANTS.— In this class are included articles having a food value such as salt,
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S. Josephine Baker
sugar, vinegar, spices, or smoke used as preservatives of meats ; or starch when added to the salts composing baking powder, where a certain amount is permissible for the purpose of absorbing moisture.
GENERAL DIRECTIONS — The ability to select fresh, wholesome meats, poultry, fish, fruits, and veg- etables, to determine readily the purity of dairy prod- ucts, and to detect adulteration or misrepresentation in all classes of foodstuffs must, in most instances, be acquired. Common sense and good reasoning powers are needed here as in every problem of life. While some adulterants can be detected only by trained chemists and by means of tests too difficult and in- volved for general use, the average housekeeper may amply protect herself from gross imposition by simply cultivating her powers of observation and by making use of a few simple tests well within her grasp and easily applied.
First — Sight, Taste, and Smell. — All are of prime importance in determining the freshness and whole- someness of foods, especially meats, poultry, fish, veg- etables, and fruits. Avoid all highly colored bottled or canned fruits or vegetables; pure preserved fruits, jams, jellies, or relishes may have a good bright color, but never have the brilliant reds and greens so often shown in the artificially colored products.^ The same is
^ The presence of aniline dyes may be detected by mixing a portion of the suspected sample with enough water to make a thin paste. Wet a piece of white wool cloth or yarn thoroughly with water and place it
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true of canned peas, beans, or Brussels sprouts; here the natural product is a dull, rather dingy green, and all bright green samples must be suspected. Foreign articles of this class are the worst offenders.
All food products should have a clean wholesome odor, characteristic of their particular class. The odor of decomposition can be readily detected; stale and musty odors are soon recognized.
It should be rarely necessary to use the sense of taste, but any food with a taste foreign to the known taste of a similar product of known purity should be discarded or at least suspected.
Second — Price — Remember that the best and pur- est food, however high priced, is cheapest in the end. Its value in purity, cleanliness, food value, and strength gives a greater proportionate return than foods priced lower than one might legitimately expect from their supposed character. To cite a few instances : pure Java and Mocha coffee cannot be retailed at twenty cents per pound ; therefore, when the housekeeper pays that price she must expect to get chicory mixed with the coffee ; if it contains no other adulterant,, she may consider herself fortunate. Cheap vanilla is not made from the vanilla bean. These beans sell at wholesale for from ten to fifteen dollars a pound, and the cheap
with the paste in an agate saucepan. Boil for ten minutes, stirring fre- quently. If a dye has been used the wool will be brightly colored; a brownish or pinkish color indicates the natural coloring matter of the fruit or vegetable. — Editor.
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extracts are made from the Tonka bean or from a chemical product known as vanilhn. These substances are not harmful, but they are not vanilla. Pure virgin olive oil is made from the flesh of olives after the stones and skin have been removed; cheaper grades are made from the stones themselves and have little food value, while the virgin oil is one of the most nu- tritious and wholesome of foods.
Such instances might be cited almost without end. Good, pure food demands a good price, and economy defeats its own purpose when it is practiced at the expense of one of the most vital necessities of health and life.
Third — ^Reliable Dealers. — Select your tradesmen with the same care you bestow in the choice of a physi- cian. A grocer or butcher who has once sold stale, adulterated, or impure wares has forfeited his right to be trusted. A man who is honestly trying to build up a good trade must have the confidence of his cus- tomers and it is to his interest to sell only worthy goods; this confidence he can gain only by proving his trustworthiness. When you are convinced of your dealer's honesty give him your trade and do not be lured away by flashy advertisements and the promise of " something for nothing."
PREPARATION FOR CHEMICAL TESTS.— Although the housekeeper will rarely need the use of any chemical tests for the purpose of determining the purity of food, the following directions must be kept
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in mind if such an expedient is deemed necessary. It will be wise, however, in the majority of cases when the presence of chemical preservatives and adulterants is suspected, to send the article to a chemist for an- alysis.
1. All refuse matter, such as shells, bones, bran, and skin, must be removed from the edible portion of the food to be tested.
2. If the sample is solid or semi-solid, divide it as finely as possible. All vegetables and meats may be minced in the common household chopping machine. Tea, coffee, whole spices, and the like may be ground or crushed in a mortar or in a spice mill.
3. Milk must be thoroughly stirred or shaken so that the cream is well mixed with the body of the milk.
FLESH FOODS— Meat— Fresh, wholesome meat is neither pink nor purple; these colors indicate either that the animal was not slaughtered or that it was diseased. Good meat is firm and elastic and when dented with the finger does not retain the impression; it has the same consistency and color throughout; the flesh is marbled, due to the presence of fat distributed among the muscular fibers; it will hardly moisten the finger when touched; it has no disagreeable odor and has a slightly acid reaction so that red litmus paper applied to it should not turn blue.
Wet, sodden, or flabby meat with jellylike fat, a strong putrid odor, and alkaline reaction should be
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avoided. These signs indicate advanced decomposition, and such meat is unfit for food.
Beef. — This meat should have a fine grain, be firm in texture, with rosy-red flesh and yellowish-white fat.
Lamb and Mutton should have a clear, hard, white fat with the lean part juicy, firm, and of rather light- red color. The flesh should be firm and close of grain.
Veal. — The meat should not be eaten unless the animal was at least six weeks old before slaughtering. The sale of this immature veal, or " bob veal " as it is sometimes called, is prohibited by law in many States. It is unwholesome and may be recognized by its soft, rather mushy consistency and bluish tinge. Good veal has a firm white fat with the lean of a pale-red color.
Pork. — This meat when fresh has a fat that is solid and pure white; if yellow and soft it should be rejected ; the lean is pink and the skin like white trans- lucent parchment.
Poultry. — Good poultry is firm to the touch, pink or yellowish in color, is fairly plump, and has a strong skin showing an unbroken surface. It has a fresh odor.
Stale poultry is flabby and shows a bluish color; it becomes green over the crop and abdomen, and the skin is already broken or easily pulled apart in handling. The odor of such a bird is disagreeable and may even be putrid.
Fish. — With the exception of the salted or pre- served varieties fish should always be perfectly fresh
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when eaten. Probably no other article of food is more dangerous to health than fish when it shows even the slightest traces of decomposition. The ability to rec- ognize the earliest signs of staleness is of the utmost importance. Fish deteriorate rapidly and should al- ways be carefully inspected before purchasing.
Fresh fish are firm to the touch, the scales moist and bright, the gills red, and the eyes clear and slightly prominent. When held flat in the hand the fish should remain rigid and the head and tail droop slightly, if at all.
Stale fish are soft and flabby, the skin is dull and the eyes sunken and often covered with a film. The tendency of the head and tail to droop is marked and the fish has a characteristic disagreeable odor. This odor of decomposition is best detected in the gills.
Lobsters and Crabs. — These shellfish should al- ways be alive when purchased. This condition is easily demonstrated by their movements, and the rule should never be disregarded.
Oysters and Clams. — Oysters should not be eaten during the months of May, June, July, and August; these are their breeding months and they are unwhole- some during that period. That oysters sometimes con- tain the germs of typhoid fever is an assured fact ; these germs are acquired not from the natural habitat of the oyster in salt water but from the fresh-water, so- called " fattening beds," where the oysters are placed for a season to remove the brackish and salty taste of
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the sea and to render them more plump. These beds are frequently subject to pollution, and the housekeeper should only purchase oysters from reliable dealers where the purity of the source of the supply is unques- tioned.
Clams are in season and may be eaten throughout the year.
All shellfish when fresh have an agreeable fresh odor. The shells should be firmly closed or should close when immersed in water and touched with the finger. If they have been removed from their shells when pur- chased, the flesh of the fish itself should be firm, clean in appearance and not covered with slime or scum; the odor should be fresh. The odor of dead or de- composed oysters and clams is pungent and dis- agreeable.
MEAT PRODUCTS— Canned or Potted Meats.— The label on cans containing meat products should state clearly the exact nature of the contents. Deception as to the character of the meat is easy to practice and dif^cult to detect by any but a trained analyst. The presence of preservatives can also only be detected by chemical analysis. As these products are practically all put on the market by the large packing houses and designed for interstate commerce, they are subject to government inspection, and, therefore, if they bear the government stamp may be considered pure. The point that the housekeeper may consider is the length of time the meat has remained in the can. Put up under
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proper precautions these canned goods retain their wholesomeness for an almost indefinite period. The heads of the cans should always present a concave sur- face; if they are convex, it is a sign of decomposition of the contents. When the can is opened the meat should have a clean appearance, free from mold or greenish hue, and the odor should be fresh and not tainted.
Sausages — If possible, sausages should be home- made, then one may be assured of their purity and freedom from adulteration.
Owing to the rapid color changes and early de- composition of fresh meat, artificial colors are often used to conceal the former, and preservatives like boric acid or saltpeter to retard the latter.
The artificial colors, such as carmine and aniline red, may be detected by observation or by warming the finely divided material on a water bath with a five per cent solution of sodium salicylate. This fluid will extract the color, if present.
Lard. — Good lard is white and granular and has a firm consistency. It has an agreeable characteristic odor and taste. The choicest leaf lard is made from the fat about the kidneys of the hog ; the cheaper grades are made from the fat of the whole animal.
FRESH VEGETABLES AND FRUITS— Vege- tables — All green vegetables to be eaten uncooked should be carefully washed and examined for insects, dirt, and foreign matter generally. The ova or eggs
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of the tapeworm may be ingested with improperly cleaned vegetables. Running water and a clean brush (kept for this purpose) should be used.
Green vegetables should have a fresh, unwilted ap- pearance; any sign of staleness or decay should cause their rejection. Overripe or underripe vegetables are harmful.
Lettuce, celery, and all leaved or stemmed vege- tables should be examined to see if the outer leaves have been removed; this may be determined by the distance of the leaves from the stem head. The gen- eral signs of disease in vegetables are softening, change of color, and mold.
The following characteristics indicate fresh and wholesome vegetables :
Asparagus. — Firm and white in the stalk with a green, compact tip.
Beans and Peas should have green, not yellow, pods, brittle, and easily snapped open. The vegetable itself should be tender^ full and fleshy, not wrinkled or shrunken.
Cabbage, crisp and firm, with a well-rounded and compact head.
Carrots, light red or yellow, with a regular, conical shape, sweet and crisp.
Cauliflower, white, compact head ; any tinge of yel- low or green generally indicates an inferior quality.
Celery, nearly white in color ; large, crisp, and solid stalks, nutty in flavor.
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Cucumbers, firm, crisp, with a smooth skin and white flesh.
Lettuce, the head close and compact; the leaves clean, crisp, and sweet. When it is too young or run- ning to seed the taste is bitter. Pale patches on the leaves are caused by mildew and are a sign of decay.
Parsnips, buff in color, with unforked roots, sweet and crisp.
Potatoes, underripe, green potatoes are unfit for food; they contain a poisonous substance which ren- ders them actually harmful. Good potatoes should have a smooth skin and few eyes; the flesh pale and of a uniform color and of a firm consistency. A rough skin, with little depressions, indicates a disease called " scab " ; dark-brown patches on the skin are due to a disease called " smut." Potatoes with such diseases are of inferior quality. If green on one side, due to exposure to the sun when growing, the potatoes are unwholesome.
Fruits. — Underripe or green fruit should never be eaten. This condition may be easily detected by the color and consistency of the fruit. Diseased or decayed fruit is known by its change of color, softening, and external mold. Spots on fruit are often caused by a fungus which lowers its quality and renders it less wholesome.
CEREALS AND THEIR PRODUCTS— Cereals. — Particularly when bought in original packages cereals are generally pure and unadulterated. When
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bought in bulk there may be found dust, dirt, worms, insects, and excessive moisture. These may all be de- termined by careful inspection. The presence of an undue amount of moisture adds greatly to the weight of cereals and is therefore a fraud. Cereals should be dry to the touch and the individual kernels or particles separate and distinct.
Flour. — By this general term is meant the ordinary wheat flour. It should not be too moist, should have a fine white appearance, remain lumpy, or hold its form, on pressure, not show any particles which cannot be crushed, and when a handful is thrown against the wall, part of it should adhere. The odor and taste should be fresh and clean and not musty or moldy.
The common adulterants are corn and rice meal. If a sample of the flour be thrown on the surface of a glassful of water, the corn and rice, being heavier, will sink; grit and sand may be detected in the same way. If the flour has been adulterated with mineral substances it may be shown by burning a portion down to an ash; the ash of pure flour should not exceed two per cent of the total amount; if mineral sub- stances are present the amount of ash will be greatly increased.
Alum is sometimes added to flour in order to give it a whiter appearance and to produce whiter and lighter bread; it is most unwholesome. It can be de- tected by the so-called ^' logwood " test, which is prepared and used as follows :
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Adulteration of Food
Make two solutions. The first: a five per cent solution of logwood chips in alcohol. The second: a fifteen per cent solution of ammonium carbonate in water. Make a paste of one teaspoonful of the flour and an equal amount of water; mix with it one- quarter of a teaspoonful of the logwood solution ; fol- low this immediately with one-quarter of a teaspoonful of the ammonium carbonate solution. If alum is present, the paste will show a lavender or blue color; if absent, the mass will become pink, fading to a dirty- brown. If the result is doubtful, set the paste aside for several hours, when the colors will show more plainly.
Bread. — Bread should be well baked and not too light or too heavy; the crust should be light brown and adherent to the substance of the bread. The center should be of even consistency, spongy, and firm; it should not pit or be soggy or doughy. The pores or holes should be of practically the same size through- out.
Exceedingly white, light, or porous bread shows the presence of alum. It may be detected by means of the solutions already mentioned in the " logwood '' test. Mix one teaspoonful of each solution and add three ounces (six tablespoonfuls) of water; pour this over a lump of bread, free from crust and about an inch square. After the bread has become thoroughly soaked, pour off the excess of liquid and dry the bread in the dish; if alum is present, the mass will show
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a violet or blue tint, more marked on drying; if absent, a brownish color will appear.
Baking Powders. — Baking powders are of three classes, all having sodium bicarbonate (baking soda) as their alkaline salt. The first style is the commonly used and wholesome mixture of cream of tartar and baking soda ; the second has calcium phosphate for the acid salt, and the third contains alum. All have a cer- tain proportion of starch to absorb moisture. Of these the alum powders are the most harmful and should be avoided. Practically all of the well-known brands of baking powder are of the first-mentioned class and wholesome, and are rarely adulterated.
DAIRY PRODUCTS— Milk._Pure milk should have a specific gravity of from 1.027 to 1.033. Its normal reaction is neutral or slightly acid; it should never be strongly acid. If it is strongly alkaline, i. e., turning red litmus paper blue, it is pretty certain that something in the way of a preservative has been added to it. When left standing for a few hours the cream should show as a slightly yellowish top layer, one- tenth or more of the whole amount; the milk below the cream should be lighter in color and with the slightest bluish tinge. If the color is of a yellowish tinge throughout, the addition of coloring matter must be suspected. " Annatto," a vegetable pigment, is used to give a " rich " tint to milk. To detect it, add one teaspoonful of baking soda to one quart of milk and immerse in it a strip of unglazed paper; in a few
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Adulteration of Food
hours examine the paper; if annatto is present, it will have become an orange color.^
If the whole milk has a blue and thin appearance, or if the cream is scant in quantity, it has probably been diluted with water. The popular idea tliat chalk is sometimes added to poor milk to make it appear of better quality is erroneous; chalk would always show as a precipitate, as it does not dissolve, and the presence of such a sediment would be a too obvious adultera- tion to be practiced.
Milk should always be kept at a temperature below 50° F. ; above that temperature the bacteria in it mul- tiply with great rapidity and render it unfit for use.
Milk may be preserved for several days if " pas- teurized " or " sterilized." Pasteurization consists of heating milk to a temperature of about 167° F., and maintaining it at that degree for twenty minutes. Sterilization means keeping the milk at a temperature of 212° F. for two hours and a half. Immediately after either process the milk should be cooled, then placed in absolutely clean, covered bottles and kept on ice. These methods are not only harmless but actually beneficial in that they destroy any disease germs that might be present.
Chemical preservatives are occasionally found in
^ A little vinegar added to heated cream or milk produces in the curd a distinct orange color if an aniline dye has been used to make the cream look " rich." The curd will be brown if annatto or caromel has been used. If pure, the curd will be white.— Editor.
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milk. They may be suspected if the milk is alkaline in reaction and has a disguised taste. The ones most commonly used are boric and salicylic acids and for- maldehyde; the two former can only be detected by chemical tests too delicate and intricate to be used by the housewife. Formaldehyde may be tested for by using a solution of one drop of a ten per cent solution of ferric chloride to one ounce of hydrochloric acid.^ Fill a small porcelain dish one-third full of this solu- tion; add an equal volume of milk and heat slowly over a flame nearly to the boiling point, giving the dish a rotary motion to break up the curd. If formal- dehyde is present, the mass will show a violet color, varying in depth with the amount present; if it is absent, the mass turns brown.
Butter. — Good butter has a fresh, sweet odor and an agreeable taste. It should be of the same color and consistency throughout, easily cut and adherent and not crumbly when molded into shapes. Pure butter is very light in color ; nearly all that is sold is colored, in order to meet the popular demand for '' yellow " butter; annatto and other vegetable and mineral sub- stances are sometimes employed for this purpose. These coloring matters are generally harmless but may be detected by dissolving a portion of the butter in alcohol; the natural color will dissolve, while foreign coloring will not. Butter should consist of eighty-five
^ This acid must be used v/ith great care ; no portion of it should ever come in contact with the skin or clothing.
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per cent fat, with the remainder water, casein, and salt. The most common methods of adulteration consist in an excess of water and the addition of oleomargarine. If an excess of water has been added it may be shown by melting the butter; the water and fat will separate in two distinct layers. Oleomargarine has a distinctive meaty smell, like that of cooked meat, and lacks the characteristic odor of pure butter. If pure butter is melted in a spoon, it will not sputter; if oleomargarine is present, it will.
The preservatives sometimes used, namely, boric and salicylic acids and formaldehyde, can only be de- tected by chemical tests.
Eggs. — Two methods may be used to detect stale eggs. First : make a solution of one part of table salt to ten parts of water and immerse the suspected tgg; if it sinks, it is perfectly fresh; if it remains in the water below the surface, it is at least three days old, and if it floats, it is five or more days old.
Second: hold the ^gg between a bright light and the eye. If it is fresh^ it will show a rosy tint through- out, without dark spots, as the air chamber is small; if not fresh, it will look cloudy, with many dark spots present.
TEA AND COFFEE.— These substances are ex- tensively adulterated, but the adulterants are almost without exception harmless.
Tea. — The commonest forms of adulteration of tea are as follows: (a) Exhausted tea leaves which have
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already been used are dried and added. Their presence may be detected by the weakness of the infusion, made from a given quantity of the suspected tea, compared with a similar infusion made from tea known to be pure, (b) Leaves from other plants are sometimes dried and added ; these are easily shown if an infusion is made and when the leaves are thoroughly wet un- rolling and comparing them, (c) Green teas may be " faced '' or colored with Prussian blue, indigo, French chalk, or sulphate of lime; black teas may be simi- larly treated with plumbago or " Dutch pink." If teas so treated are shaken up in cold water the coloring matter will wash off. (d) Sand and iron filings are occasionally added for weight; observation, and the fact that they sink when tea is thrown in water, will show their presence. Iron filings may be readily found by using a magnet, (e) The presence of starch may be shown by washing the tea in cold water, straining it, and testing the solution in the following manner: dissolve one-half teaspoonful of potassium iodide in three ounces of water and add as much iodine as the solution will dissolve; a few drops of this solution added to the suspected sample will give a blue color if starch is present.
Coffee. — Coffee should always be purchased in the bean, as ground coffee is much more frequently adul- terated and the foreign substances are more difficult to detect.
The adulterants commonly used are : chicory, peas, 105
Adulteration of Food
beans, peanuts, and pellets of roasted wheat flour, rye, corn, or barley.
Fat globules are always present in pure coffee ; their presence may be shown by the fact that imitation cof- fee sinks in water, while pure coffee floats.
Chicory is the most frequently used adulterant; it is added for flavor and to produce a darker infusion, thus giving the impression of greater strength. It is perfectly harmless and as a drink is actually preferred by some people. Its detection is comparatively easy. Chicory grains are dark, gummy, soft, and bitter; cof- fee grains are hard and brittle ; a small amount put in the mouth will demonstrate the difference. Chicory will often adhere to the wheels of a coffee grinder, clog- ging them on account of its gummy consistency.
When a sample of adulterated coffee is thrown in water the pure coffee floats and leaves the water unstained ; chicory sinks almost instantly, coloring the water, while peas and beans sink more slowly but also color the water.
Peas and beans are also detected by the polished appearance of the broken or crushed grains in marked contrast to the dull surface of crushed coffee.
The presence of peas, beans, rye, wheat, bread crumbs, and allied substances may be shown by the fact that they all contain starch.
Make a ten per cent infusion of the suspected coffee; filter it, and decolorize the solution by boiling it with a piece of animal charcoal. Test the decolorized solu-
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tion by slowly adding a few drops of the " potassium- iodide-iodine solution," directions for preparing which were given under heading of " Tea." A resulting blue color will indicate the presence of starch.
COCOA AND CHOCOLATE.— The adulterants of these substances are generally harmless, as they usually consist of flavoring extracts, sugar, starch, flour, and animal fats. No tests other than flavor, consistency, and smoothness need be considered. Good cocoa and chocolate should be slightly bitter, with a pleasant characteristic odor and taste ; they should have a smooth, even consistency and be free from grit or harsh particles.
CANNED AND BOTTLED VEGETABLES AND FRUITS. — In general, acid substances, such as tomatoes and fruits, should not be canned in tin, as the action of the acid tends to dissolve the tin. It is better, therefore, to purchase these articles in glass.
After opening the can the odor and appearance of the contents should be noted. The odor should be clean and fresh, and the slightest trace of any sour, musty, or disagreeable smell should cause the rejec- tion of the food. The appearance should be clean, with no mold; the consistency and color of the fruit or vegetables should be uniform throughout. If the color is brighter than that of a similar article when canned at home, the presence of artificial coloring mat- ter must be suspected. The brilliant green of some
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brands of peas, beans, or Brussels sprouts is pro- duced by the addition of the salts of copper. This may be proved by leaving the blade of a penknife in the contents of the can for a short time; if copper is present it will be deposited on, and discolor, the blade.
Brightly colored fruits should excite suspicion; this same dictum applies to all brightly colored jams and jellies, as the colors are usually produced by the addition of carmine or aniline red.
The presence of preservatives, salicylic and boric acids, the benzoates, etc., can only be proved by deli- cate chemical tests.
SUGAR. — Pure granulated or powdered sugar is white and clean. The presence of glucose should be suspected in sugar sold below the market price; it is perfectly harmless, but has a sweetening power of only about two-thirds that of sugar and is added on account of its cheapness and to increase the bulk.
If sand, dirt, or flour are present they may be detected by observation, or by washing the suspected sample in water; flour will not dissolve, sand will sink, and dirt will discolor the water.
SPICES. — Spices should be bought whole and ground in a spice mill as needed; if this is done, there need be little fear of their impurity, for whole spices are difficult to simulate or adulterate. Ground spices may be adulterated with bark, flour, starches, or arrow- root ; these adulterants are harmless, but are fraudulent,
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as they increase the bulk and decrease the strength. Their actual presences can only be demonstrated by a microscopical or chemical examination.
Peppers — Black pepper is made from the whole berry ; white pepper is made from the same berry with the outer husk removed. The adulterants are usually inert and harmless substances, such as flour, mustard, or linseed oil; their presence is obviated by the use of the whole peppercorns, ground as needed.
Red Pepper. — This may be adulterated with red lead ; when pure it will be entirely suspended in water ; if a sediment falls it is probably red lead.
Mustard. — Practically all of the adulterants of mustard can only be detected by intricate chemical tests. The presence of turmeric may be detected by the appearance of an orange-red color when ammonia is added to a solution of the sample.
Tomato Catsup. — Artificial dyestuffs are common, giving a brilliant crimson or magenta color. Such catsup does not resemble the natural dull red or brown color of the homemade article.
Preservatives, such as boric, salicylic, or benzoic acids and their salts, are sometimes added. While their presence cannot be condoned, yet they are usu- ally present in small amounts and therefore practically harmless.
Pickles. — These should be of a dull-green color. The bright emerald green sometimes observed is due to the presence of the salts of copper; this may be
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proved by dipping the blade of a penknife in the hquor, as described under the heading of " Canned Goods."
Alum is sometimes used as a preservative and in order to make the pickles crisp. Its presence may be demonstrated by means of the " logwood " test men- tioned under the heading of " Flour."
VINEGAR. — Cider vinegar is of a brownish-yel- low color and possesses a strong odor of apples.
Wine vinegar is light yellow if made from white wine, and red if made from red wine.
Malt vinegar is brown and has an odor suggestive of sour beer.
Glucose vinegar has the taste and odor of fermented sugar.
Molasses vinegar has the distinctive odor and taste of molasses.
OLIVE OIL. — Pure olive oil has a pleasant, bland taste and a distinctive and agreeable odor, unmistak- able in character for that of any other oil. The finest virgin oil is pale green in color, the cheaper grades are light yellow.
The adulterants consist of cotton-seed, corn, mus- tard, and peanut oils.
When pure olive oil is shaken in a glass or porce- lain dish with an equal quantity of concentrated nitric or sulphuric acid ^ it turns from a pale to a dark green color in a few minutes ; if under this treatment a red-
* These acids must be used with great care. They should never be allowed to come in contact with the skin or clothing.
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dish to an orange or brown color is produced the presence of a foreign vegetable oil is to be suspected.
FLAVORING EXTRACTS— Vanilla.— This may be wholly or in part the extract of the Tonka bean or may be made from a chemical substance known as vanillin. The best practical working tests as to its purity are the price, taste, and odor. The distinctive odor and taste of vanilla are characteristic and can- not be mistaken.^
Lemon. — This extract is often made from tartaric or citric acid. They may be tested for as follows : to a portion of the extract in a test tube add an equal volume of water to precipitate the oil; filter, and add one or two drops of the filtrate to a test tube full of cold, clear limewater; if tartaric acid is present a pre- cipitate will fall to the bottom of the tube. Filter off this precipitate (if present) and heat the contents of the tube; if citric acid is present it will precipitate in the hot limewater.
^ Add a little sugar~of-lead solution to the suspected extract; true vanilla extract will give a yellowish-brown precipitate and a pale, straw- colored Hquid. If the extract is artificial, the addition of the lead solution will have little or no effect. — Editor.
Footnote. — Dr. Baker wishes to acknowledge her indebtedness to the following authorities and the volumes mentioned for many helpful suggestions. Pearman and Moore, "Aids to the Analysis of Foods and Drugs " ; Albert E. Leach, " Food Inspection and Analysis " j Francis Vacher, " Food Inspector's Hand Book."
Ill
CHAPTER II Mushroom Poisoning
Symptoms — Treatment — How to Tell Mushrooms — The Common Kind — Other Varieties — The Edible Puff ball — Poisonous Mushrooms Frequently Mistaken.
MUSHROOM POISONING. — Vomiting, cramps, diarrhea, pains in legs ; possibly confusion, as i£ drunk, stupidity, followed by excitement, and perhaps convulsions. Lips and face may be blue. Pulse may be weak.
First Aid Rule i. — Rid the stomach and bowels of remaining poison. Give emetic of mustard, tablespoon- ful in three glasses of warm water, unless vomiting is already excessive. When vomiting ceases, give table- spoonful of castor oil, or compound cathartic pill. Give no salts. Also empty bowels with injection of tablespoonful of glycerin in pint of warm soapsuds and water.
Rule 2. — Antidote the poison. Give a cup of strong coffee and fifteen drops of tincture of bella- donna to adult. Repeat both once, after two hours have passed.
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Rule S' — ^^^^ (^^^d stimulate. Put patient to bed. Give whisky, a tahkspoonfid in tzvice as much water. Give tincture of digitalis, ten drops every two hours, till two or three doses are taken by adtdt.
Symptoms. — Vomiting and diarrhea come on in a few hours to half a day, with cramps in the stomach and legs. The face and lips may grow blue. There is great prostration. In the case of poisoning by the dy ama- nita, stupor may appear early, the patient acting as if drunk, and difficult breathing may be a noticeable symp- tom. Afterwards the patient becomes excited and con- vulsions develop. The pulse becomes weak and slow\ The patient may die in a few hours, or may linger for three or four days. If treatment be thorough, recov- ery may result.
Treatment — Unless vomiting has already been ex- cessive, the patient should receive a tablespoonful of mustard mixed with a glassful of tepid water. After the vomiting ceases he should receive a tablespoonful of castor oil, or any cathartic except salts. If the ca- thartic is vomited, he should receive an injection into the rectum of a tablespoonful of glycerin mixed with a pint of soapsuds and water. Coffee and atropine (or belladonna) are the best antidotes.
If a physician be secured, he will probably give a hypodermic injection of atropine. If a physician is not procurable, the patient should receive a cup of strong coffee, and a dose of ten or fifteen drops of tinc-
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How to know Mushrooms
ture of belladonna in a tablespoonful of water, if an adult. This dose should be repeated once after the lapse of two hours. The patient should be kept in bed, a bedpan being used when the bowels move.
When the pulse begins to grow weak, two table- spoonfuls of whisky and ten drops of the tincture of digitalis should be given to an adult in quarter of a glass of hot water. The digitalis should be repeated every two hours till three or four doses have been taken. The patient must be kept warm with hot-water bottles and blankets.
HOW TO KNOW MUSHROOMS— One-sixth of one of the poisonous mushrooms has caused death. It is, therefore, impossible to exert too much care in selecting them for food. A novice would much better learn all the characteristics of edible and poisonous mushrooms in the field from an expert before attempt- ing to gather them himself, and should not trust to book descriptions, except in the case of the few edible species described hereafter. It is not safe for a nov- ice to gather the immature or button mushrooms, be- cause it is much more difficult to determine their char- acteristics than those of the full grown. As reference books, the reader is advised to procure Bulletin No. 15 of the United States Department of Agriculture, en- titled " Some Edible and Poisonous Fungi," by Dr. W. G. Farlow, which will be sent without charge on request by the Agricultural Department at Washington ; ** Stud- ies of American Fungi,'' by Atkinson, and Miss Mar-
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shall's " Mushroom Book," all of which are fully illus- trated, and will prove helpful to those interested in edible fungi.
There are no single tests by which one can dis- tinguish edible from poisonous fungi, such as taste, odor, the blackening of a silver spoon, etc., although contrary statements have been made. Even when the proper mushrooms have been eaten, ill effects, death itself, may follow if the mushrooms have been kept too long, have been insufficiently cooked, have been eaten in too large a quantity (especially by children), or if the consumer is the possessor of an unhappy idiosyn- crasy toward mushrooms.
No botanic distinction exists between toadstools and mushrooms ; mushrooms may be regarded as edible toadstools. They are all, botanically speaking, edible or poisonous fungi. A description follows of the five kinds of fungi most commonly eaten, and the poisonous species which may be mistaken for them.
EDIBLE MUSHROOMS. — I. The Common Mushroom (Agaricus Campestris) . — The fungi called agarici are those which have gills, that is, little plates which look like knife blades on the under surface of the top of the mushroom, radiating outward from the stem like the spokes of a wheel. This is the species most frequently grown artificially, and sold in the mar- kets. The top or cap of this mushroom is white, or of varying shades of brown, and measures from one and a half to three or even four inches in diameter. It
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Fig. 35. THE FIELD MUSHROOM.
{Agaricus Campestris.) An edible variety ; very common.
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is found in the latter part of August, in September, and in October, growing in clusters on pastures, fields, and lawns.
The gills are pink or salmon colored in the newly expanded specimen; but as it grows older, or after it is picked, the gills turn dark purple, chestnut brown, or black. This is the important point to remember, since the poisonous species mistaken for it all have white gills. The gills end with abrupt upward curves at the center of the cap without being attached to the stem. In the young mushroom, when the cap is folded down about the stem, the gills are not noticeable, as they are covered by a veil or filmy membrane, a part of which remains attached to the stem (when the top expands), as a ring or collar about the stem a little more than halfway up from the ground. The stem is solid and not hollow, and there is no bulbous enlargement at the base of the stem, surrounded by scales or a collar, as occurs in the Hy amanita and other poisonous species. Neither the campestris nor any other mushroom should be eaten when over a day old, since decomposition quickly sets in.
2. Horse Mushroom (Agaricus Arvensis). — This species may be considered with the foregoing, but it differs in being considerably larger (measuring four to ten inches across) and in having a more shiny cap, of a white or brown hue. The ring about the stem is no- ticeably wider and thicker, and is composed of two dis- tinct layers. The gills are white at first, turning dark
117
Fig. 36.
THE HORSE MUSHROOM.
{Agaricus Arvensis.)
This variety is edible.
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brown comparatively late, and the stem is a little hol- low as it matures. In some localities it is more com- mon than the campestris in fields and pastures, while in other places it is found only in rich gardens, about hot beds, or in cold frames. It is not distinguished from the ccmtpestris by market people, but is often sold with the latter.
3. Shaggy Mane, Ink Cap, or Horsetail Fungus (Coprinus Comatus). — This mushroom possesses the most marked characteristics of any of the edible spe- cies; it would seem impossible to mistake its identity from written descriptions and illustrations. It is con- sidered by many superior in flavor to the campestris.
The top or cap does not expand in this mushroom, until it begins to turn black, but remains folded down about the stem like a closed umbrella. Mature spec- imens are usually three to five, occasionally from eight to ten, inches high. The stem is hollow. The inside of the cap or gills and the stem are snow white. The outer surface of the cap, which is white in young plants, becomes of a faint, yellow-brown or tawny color in mature specimens, and also darker at the top. Del- icate scales often rolled up at their lower ends are seen on the exterior of the cap, more readily in mature mushrooms, hence the name " shaggy mane." There is a ring around the stem at the lower margin of the cap, and it is so loosely attached to either the cap or stem that it sometimes drops down to the base of the latter.
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M
U
Fig. 37.
THE HORSE-TAIL FUNGUS.
{Coprinus Comatus.)
Edible ; cut shows entire plant and section,
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The most salient feature of shaggy mane is the change which occurs when it is about a day old; it turns black and dissolves away into an inky fluid, whence the other common name " ink cap." The mushroom should not be eaten when in this condition. The ink cap is usually found growing in autumn, rarely in summer, in richer earth than the common mushroom. One finds it in heaps of street scrapings, by roadsides, in rich lawns, in soils filled with decom- posing wood and in low, shaded, moist grounds.
4. Fairy-ring Mushroom (Marasmius Oreades). — This species usually grows on lawns, in clusters which form an imperfect circle or crescent. The ring increases in size each year as new fungi grow on the outside, while old ones toward the center of the circle perish. This mushroom is small and slender, and rarely exceeds two inches in breadth. The cap and the tough and tubular stem are buf¥, and the gills, few in number and bulging out in the middle, are of a lighter shade of the same color. There is no ring about the stem. Several crops of the fairy-ring mushroom are produced all through the season, but the most prolific growth appears after the late fall rains. There are other fungi forming rings, some of which are poison- ous, and they may not be easily distinguished from the edible species; hence great care is essential in gather- ing them. The under surface of the cap is brown or blackish in the mature plants of poisonous species.
5. Edible Puffball (Lycoperdon Cyathiforme) . —
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Edible Mushrooms
Edible puffballs grow in open pastures, and on lawns and grassplots, often forming rings. They are spherical in form, generally from one and a half to two inches, oc-
FlG. 38.
THE FAIRY-RING MUSHROOM.
{Marasmius Oreades.)
An edible variety.
casionally six inches, in diameter, broad and somewhat flattened at the top, and tapering at the base, white or brown outside. They often present an irregularly checkered appearance, owing to the fact that the white interior shows between the dark raised parts. The
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Fig. 39.
THE EDIBLE PUFFBALL.
{Lycoperdon Cyat hi forme.)
Upper illustration shows entire plant ; lower, a section.
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Poisonous Mushrooms
interior is at first pure white and of solid consistency, but later becomes softer and yellowish, and then con- tains an amber-colored juice. After the puff ball has matured, the contents change into a brown, dustlike mass, and the top falls off ; and it is then inedible. All varieties of puffball with a pure white interior are harmless, if eaten before becoming crumbly and pow- dery. There is only one species thought to be poison- ous, and that has a yellow-brown exterior, while the interior is purple-black, marbled with white.
POISONOUS MUSHROOMS FREQUENTLY MISTAKEN.
To escape eating poisonous mushrooms do not gather the buttons, and he suspicious of those growing in woods and shady spots that show any bright hue, or have a scaly or dotted cap, or white gills} By so doing the following species will be avoided.
Fly Amanita {Amanita Muscaria). — Infusions of this mushroom made by boiling in water are used to kill flies. This species grows in woods and shady places, by roadsides, and along the borders of fields, and is much commoner than the campestris in some localities. It prefers a poor, gravelly soil, and is found in summer.
The stem is hollow and its gills are white. The
* The shaggy mane has white gills, but its other features are char- acteristic.
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Fig. 40.
A POISONOUS FUNGUS.
{Amanita Muscaria^
The Fly Agaric.
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Fig. 41- THE DEADLY AGARIC.
{Amanita Phalloides)
This variety is very poisonous.
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cap is variously colored, white, orange, yellow, or even brilliant red, and dotted over with corklike particles or warty scales which are easily rubbed off. There is a large, drooping collar about the upper part of the hollow, white stem, and the latter is scaly below with a bulbous enlargement at its base.
The young mushrooms, or buttons, do not exhibit the dotted cap, and the bulbous scaly base may be left in the ground when the mushroom is picked. The Hy amanita is usually larger than the common mush- room.
Death Cup or Deadly Agaric {Amanita Phal- loides). — ^This species is more fatal in its effects than the preceding. Its salient feature is a bulbous base surmounted and surrounded by a collar or cup out of which the stem grows. This is often buried beneath the ground, however, so that it may escape notice. The gills and stem are white like the preceding, but the cap is usually not dotted but glossy, white, green- ish, or yellow. There is also a broad, noticeable ring about the stem, as in the Hy amanita. This mushroom frequents moist, shady spots, also along the borders of fields. It occurs singly, and rarely in fields or pastures.
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Part III
THE HOUSE AND GROUNDS
BY GEORGE M. PRICE
Acknowledgment
We beg to tender grateful acknowledgment to au- thor and publisher for the use of Dr. George M. Price's valuable articles on sanitation. The following ex- tracts are taken from Dr. Price's " Handbook on San- itation," published by John Wiley & Son, and are cov- ered by copyright.
CHAPTER I t Soil and Sites
Definition. — By the term " soil " we mean the su- perficial layer of the earth, a result of the geological disintegration of the primitive rock by the action of the elements upon it and of the decay of vegetable and ani- mal life.
Composition. — Soil consists of solids, v^ater, and air.
Solids. — The solid constituents of the soil are in- organic and organic in character.
The inorganic constituents are the various minerals and elements found alone^ or in combination, in the earth, such as silica, aluminum, calcium, iron, carbon, sodium, chlorine, potassium, etc.
The characteristics of the soil depend upon its con- stituents, and upon the predominance of one or the other of its composing elements. The nature of the soil also depends upon its physical properties. When the disintegrated rock consists of quite large particles, the soil is called a gravel soil. A sandy soil is one in which the particles are very small. Sandstone is con- solidated sand. Clay is soil consisting principally of
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Soil and Sites
aluminum silicate ; in chalk , soft calcium carbonate pre- dominates.
The organic constituents of the soil are the result of vegetable and animal growth and decomposition in the soil. ^
Ground Water — Ground water is that continuous body or sheet of water formed by the complete filling and saturation of the soil to a certain level by rain water; it is that stratum of subterranean lakes and rivers, filled up with alluvium, which we reach at a higher or lower level when we dig wells.
The level of the ground water depends upon the un- derlying strata, and also upon the movements of the subterranean water bed. The relative position of the impermeable underlying strata varies in its distance from the surface soil.. In marshy land the ground water is at the surface ; in other places it can be reached only ly deep borings. The source of the ground wa- ter is the rainfall, part of which drains into the porous soil until it reaches an impermeable stratum, where it collects.
The movements of the ground water are in two directions — horizontal and vertical. The horizontal or lateral movement is toward the seas and adjacent wa- ter courses, and is determined by hydrostatic laws and topographical relations. The vertical motion of the ground water is to and from the surface, and is due to the amount of rainfall, the pressure of tides, and water courses into which the ground water drains. The
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vertical variations of the ground water determine the distance of its surface level from the soil surface, and are divided into a persistently low-water level, about fifteen feet from the surface ; a persistently high-water level, about five feet from the surface, and a fluctuating level, sometimes high, sometimes low.
Ground Air. — Except in the hardest granite rocks and in soil completely filled with water the interstices of the soil are filled with a continuation of atmospheric air, the amount depending on the degree of porosity of the soil. The nature of the ground air differs from that of the atmosphere only as it is influenced by its location. The principal constituents of the air — nitro- gen, oxygen, and carbonic acid — are also found in the ground air, but in the latter the relative quantities of O and CO2 are different.
AVERAGE COMPOSITION OF ATMOSPHERIC AIR IN lOO VOLUMES
Nitrogen 79.00 per cent.
Oxygen 20,96 "
Carbonic acid 0.04 "
AVERAGE COMPOSITION OF GROUND AIR
Nitrogen 79.00 per cent.
Oxygen 10.35 "
Carbonic acid 9.74 "
Of course, these quantities are not constant, but vary in different soils, and at different depths, times, etc. The greater quantity of CO2 in ground air is due to the process of oxidation and decomposition taking place
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Soil and Sites
in the soil. Ground air also contains a large quan- tity of bacterial and other organic matter found in the soil.
Ground air is in constant motion, its movements depending upon a great many factors, some among these being the winds and movements of the atmos- pheric air, the temperature of the soil, the surface tem- perature, the pressure from the ground water from below, and surface and rain water from above, etc.
Ground Moisture. — The interstices of the soil above the ground-water level are filled with air only, when the soil is absolutely dry ; but as such a soil is very rare, all soils being more or less damp, soil usually contains a mixture of air and water, or what is called ground moisture.
Ground moisture is derived partly from the evap- oration of the ground water and its capillary absorp- tion by the surface soil, and partly by the retention of water from rains upon the surface. The power of the soil to absorb and retain moisture varies according to the physical and chemical, as well as the thermal, prop- erties of the soil.
Loose sand may hold about 2 gallons of water per cubic foot ; granite takes up about 4 per cent of mois- ture ; chalk about 1 5 per cent ; clay about 20 per cent ; sandy loam 33 to 35 per cent ; humus ^ about 40 per cent.
Ground Temperature. — The temperature of the soil is due to the direct rays of the sun, the physicochemi-
* Humus is vegetable mold; swamp muck; peat; etc. — Editor. 134
George M. Price
cal changes in its interior, and to the internal heat of the earth.
The ground temperature varies according to the annual and diurnal changes of the external tempera- ture; also according to the character of the soil, its color, composition, depth, degree of organic oxidation, ground-water level, and degree of dampness. In hot weather the surface soil is cooler, and the subsurface soil still more so, than the surrounding air; in cold weather the opposite is the case. The contact of the cool soil with the warm surface air on summer even- ings is what produces the condensation of air moisture which we call dew.
Bacteria. — Quite a large number of bacteria are found in the soil, especially near the surface, where chemical and organic changes are most active. From 200,000 to 1,000,000 bacteria have been found in i c.c. of earth. The ground bacteria are divided into two groups — saprophytic and pathogenic. The saprophytic bacteria are the bacteria of decay, putrefaction, and fermentation. It is to their benevolent action that vegetable and animal debris is decomposed, oxidized, and reduced to its elements. To these bacteria the soil owes its self-purifying capacity and the faculty of dis- integrating animal and vegetable debris.
The pathogenic bacteria are either those formed during the process of organic decay, and which, intro- duced into the human system, are capable of producing various diseases, or those which become lodged in the
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Soil and Sites
soil through the contamination of the latter by ground water and air, and which find in the soil a favorable lodging ground, until forced out of the soil by the movements of the ground water and air.
Contamination of the Soil. — The natural capacity of the soil to decompose and reduce organic matter is sometimes taxed to its utmost by the introduction into the soil of extraneous matters in quantities which the soil is unable to oxidize in a given period. This is called contamination or pollution of soil, and is due: (i) to surface pollution by refuse, garbage, animal and human excreta; (2) to interment of dead bodies of beasts and men; (3) to the introduction of foreign deleterious gases, etc.^
Pollution by Surface Refuse and Sewage. — This occurs where a large number of people congregate, as in cities, towns, etc., and very seriously contaminates the ground by the surcharge of the surface soil with sewage matter, saturating the ground with it, pollut- ing the ground water from which the drinking water is derived, and increasing the putrefactive changes taking place in the soil. Here the pathogenic bacteria abound, and, by multiplying, exert a very marked in- fluence upon the health by the possible spread of in- fectious diseases. Sewage pollution of the soils and of the source of water supply is a matter of grave im-
* A leak in a gas main, allowing the gas to penetrate the soil, will destroy trees, shrubbery, or any other vegetation with which it conies in contact. — Editor.
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George M. Price
portance, and is one of the chief factois ot high mor- taHty in cities and towns.
Interment of Bodies. — The second cause of soil contamination is also of great importance. Owing to the intense physicochemical and organic changes tak- ing place within the soil, all dead animal matter in- terred therein is easily disposed of in a certain time, being reduced to the primary constituents, viz., am- monia, nitrous acid, carbonic acid, sulphureted and carbureted hydrogen, etc. But whenever the number of interred bodies is too great, and the products of de- composition are allowed to accumulate to a very great degree, until the capacity of the soil to absorb and oxi- dize them is overtaxed, the soil, and the air and water therein, are polluted by the noxious poisons produced by the processes of decomposition.
Introduction of Various Foreign Materials and Gases. — In cities and towns various pipes are laid in the ground for conducting certain substances, as illu- minating gas, fuel, coal gas, etc. ; the pipes at times are defective, allowing leakage therefrom, and permitting the saturation of the soil with poisonous gases which are frequently drawn up by the various currents of ground air into the open air and adjacent dwellings.
Influence of the Soil on Health. — The intimate re- lations existing between the soil upon which we live and our health, and the marked influence of the soil on the life and well-being of man, have been recog- nized from time immemorial.
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Soil and Sites
The influence of the soil upon health is due to: (i) the physical and chemical character of the soil;
(2) the ground-water level and degree of dampness;
(3) the organic impurities and contamination of the soil.
The physical and chemical nature of the soil, irre- spective of its v^ater, moisture, and air, has been re- garded by some authorities as having an effect on the health, growth, and constitution of man. The peculiar disease called cretinism, as well as goitre, has been attributed to a predominance of certain chemicals in the soil.
The ground-water level is of great importance to the well-being of man. Professor Pettenkofer claimed that a persistently low water level (about fifteen feet from the surface) is healthy, the mortality being the lowest in such places ; a persistently high ground-water level (about five feet from the surface) is unhealthy; and a fluctuating level, varying from high to low, is the most unhealthy, and is dangerous to life and health. Many authorities have sought to demonstrate the in- timate relations between a high water level in the soil and various diseases.
A damp soil, viz., a soil wherein the ground mois- ture is very great and persistent, has been found inimical to the health of the inhabitants, predisposing them to various diseases by the direct effects of the dampness itself, and by the greater proneness of damp ground to become contaminated with various patho-
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genie bacteria and organisms which may be drawn into the dwelHngs by the movements of the ground air. As a rule, there is very Httle to hinder the ground air from penetrating the dwelHngs of man, air being drawn in through cellars by changes in temperature, and by the artificial heating of houses.
The organic impurities and bacteria found in the soil are especially abundant in large cities, and are a cause of the evil influence of soil upon health. The im- purities are allowed to drain into the ground, to pollute the ground water and the source of water supply, and to poison the ground air, loading it with bacteria and products of putrefaction, thus contaminating the air and water so necessary to life.
Diseases Due to Soil. — A great many diseases have been thought to be due to the influence of the soil. An astiological relation had been sought between soil and the following diseases : malaria, paroxysmal fevers, tuberculosis, neuralgias, cholera, yellow fever, bubonic plague, typhoid, dysentery, goiter and cretinism, teta- nus, anthrax, malignant QEdema, septicaemia, etc.
Sites. — From what we have already learned about the soil, it is evident that it is a matter of great im- portance as to where the site for a human habitation is selected, for upon the proper selection of the site depend the health, well-being, and longevity of the in- habitants. The requisite characteristics of a healthy site for dwellings are: a dry, porous, permeable soil; a low and nonfluctuating ground-water level, and a
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Soil and Sites
soil retaining very little dampness, free from organic impurities, and the ground water of which is well drained into distant water courses, while its ground air is uncontaminated by pathogenic bacteria. Ex- posure to sunlight, and free circulation of air, are also requisite.
According to Parkes, the soils in the order of their fitness for building purposes are as follows : ( i ) prim- itive rock; (2) gravel, with pervious soil; (3) sand- stone; (4) limestone; (5) sandstone, with impervious subsoil; (6) clays and marls; (7) marshy land, and (8) made soils.
It is very seldom, however, that a soil can be se- cured having all the requisites of a healthy site. In smaller places, as well as in cities, commercial and other reasons frequently compel the acquisition of and build- ing upon a site not fit for the purpose ; it then becomes a sanitary problem how to remedy the defects and make the soil suitable for habitation.
Prevention of the Bad Effects of the Soil on Health. — The methods taught by sanitary science to improve a defective soil and to prepare a healthy site are the following :
(i) Street paving and tree planting.
(2) Proper construction of houses.
(3) Subsoil drainage.
Street Paving serves a double sanitary purpose. It prevents street refuse and sewage from penetrating the ground and contaminating the surface soil, and it
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George M. Price
acts as a barrier to the free ascension of deleterious ground air.^
Tree Planting serves as a factor in absorbing the ground moisture and in oxidizing organic im- purities.
The Proper Construction of the House has for its purpose the prevention of the entrance of ground moisture and air inside the house by building the foundations and cellar in such a manner as to entirely cut off communication between the ground and the dwelling. This is accomplished by putting under the foundation a solid bed of concrete, and under the foun- dation walls damp-proof courses.
The following are the methods recommended by the New York City Tenement House Department for the
* Town and village paving plans will benefit by knowledge of the recent satisfactory experience of New York City authorities in paving with wood blocks soaked in a preparation of creosote and resin. As compared with the other two general classes of paving, granite blocks, and asphalt, these wood blocks are now considered superior.
The granite blocks are now nearly discarded in New York because of their permeability, expense, and noise, being now used for heavy traffic only.
Asphalt is noiseless and impermeable (thereby serving the " double sanitary purpose" mentioned by Dr. Price).
But the wood possesses these qualities, and has in addition the ad- vantage of inexpensiveness, since it is more durable, not cracking at winter cold and melting under summer heat like the asphalt ; and there is but slight cost for repairs, which are easily made by taking out the sep- arate blocks.
These " creo-resinate " wood blocks, recently used on lower Broad- way, Park Place, and the congested side streets, are giving admirable results. — Editor.
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Soil and Sites
water-proofing and damp-proofing of foundation walls and cellars:
Water-proofing and Damp-prooUng of Foundation Walls. — " There shall be built in with the foundation walls, at a level of six (6) inches below the finished floor level, a course of damp-proofing consisting of not less than two (2) ply of tarred felt (not less than fifteen (15) pounds weight per one hundred (100) square feet), and one (i) ply of burlap, laid in al- ternate layers, having the burlap placed between the felt, and all laid in hot, heavy coal-tar pitch, or liquid asphalt, and projecting six (6) inches inside and six (6) inches outside of the walls.
" There shall be constructed on the outside surface of the walls a water-proofing lapping on to the damp- proof course in the foundation walls and extending up to the soil level. This water-proofing shall consist of not less than two (2) ply of tarred felt (of weight specified above), laid in hot, heavy coal-tar pitch, or liquid asphalt, finished with a flow of hot pitch of the same character. This water-proofing to be well stuck to the damp course in the foundation walls. The layers of felt must break joints.
Water-proofing and Damp-prooUng of Cellar Floors. — " There shall be laid, above a suitable bed of rough concrete, a course of water-proofing consist- ing of not less than three (3) ply of tarred felt (not less than fifteen (15) pounds weight per one hun- dred (100) square feet), laid in hot, heavy coal-tar
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George M. Price
CONCRETE
THREE-PLY
WATER PROOFtNC
For Brick Wall.
eROUtrt) LEWEL
■CCWCRETE
THREE-PLY
WATER PROOrtKfi
"-CONCRETE
For Stone Wall.
Fig. 4.
CONCRETE FOUNDATION AND DAMP-PROOF COURSE.
Soil and Sites
pitch, or liquid asphalt, finished with a flow of hot pitch of the same character. The felt is to be laid so that each layer laps two-thirds of its width over the layer immediately below, the contact surface being thoroughly coated with the hot pitch over its entire area before placing the upper layer. The water- proofing course must be properly Japped on and se- cured to the damp course in the foundation walls/*
Other methods of damp-proofing foundations and cellars consist in the use of slate or sheet lead instead of tar and tarred paper. An additional means of preventing water and dampness from coming into houses has been proposed in the so-called " dry areas," which are open spaces four to eight feet wide between the house proper and the surrounding ground, the open spaces running as deep as the foundation, if possible. The dry areas are certainly a good preventive against dampness coming from the sides of the house.
Subsoil Drainage. — By subsoil drainage is meant the reducing of the level of the ground water by drain- ing all subsoil water into certain water courses, either artificial or natural. Subsoil drainage is not a modern discovery, as it was used in many ancient lands, and was extensively employed in ancient Rome, the valleys and suburbs of which would have been uninhabitable but for the draining of the marshes by the so-called " cloaccB " or drains, which lowered the ground-water level of the low parts of the city and made them fit to build upon. The drains for the conduction of sub-
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soil water are placed at a certain depth, with a fall toward the exit. The materials for the drain are either stone and gravel trenches, or, better, porous earthenware pipes or ordinary drain tile. The drains must not be impermeable or closed, and sewers are not to be used for drainage purposes. Sometimes open, V-shaped pipes are laid under the regular sewers, if these are at the proper depth.
By subsoil drainage it is possible to lower the level of ground water wherever it is near or at the surface, as in swamps, marsh, and other lands, and prepare lands previously uninhabitable for healthy sites.
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CHAPTER II Ventilation
Definition. — The air within an uninhabited room does not differ from that without. If the room is oc- cupied by one or more individuals, however, then the air in the room soon deteriorates, until the impurities therein reach a certain degree incompatible with health. This is due to the fact that with each breath a certain quantity of CO2, organic impurities, and aqueous vapor is exhaled ; and these products of respiration soon sur- charge the air until it is rendered impure and unfit for breathing. In order to render the air pure in such a room, and make life possible, it is necessary to change the air by withdrawing the impure, and sub- stituting pure air from the outside. This is ventilation.
Ventilation, therefore, is the maintenance of the air in a confined space in a condition conducive to health ; in other words, " ventilation is the replacing of the impure air in a confined space by pure air from the outside."
Quantity of Air Required What do we regard
as impure air ? What is the index of impurity ? How much air is required to render pure an air in a given space, in a given time, for a given number of people?
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How often can the change be safely made, and how ? These are the problems of ventilation.
An increase in the quantity of CO2 [carbon dioxide gas], and a proportionate increase of organic impuri- ties, are the results of respiratory vitiation of the air; and it has been agreed to regard the relative quantity of CO2 as the standard of impurity, its increase serv- ing as an index of the condition of the air. The nor- mal quantity of CO2 in the air is 0.04 per cent, or 4 volumes in 10,000; and it has been determined that whenever the CO2 reaches 0.06 per cent, or 6 parts per 10,000, the maximum of air vitiation is reached — a point beyond which the breathing of the air becomes dangerous to health.
We therefore know that an increase of 2 volumes of CO 2 in 10,000 of air constitutes the maximum of admissible impurity; the difference between 0.04 per cent and 0.06 per cent. Now, a healthy average adult at rest exhales in one hour 0.6 cubic foot of CO2. Having determined these two factors — the amount of CO2 exhaled in one hour and the maximum of admis- sible impurity — we can find by dividing 0.6 by 0.0002 (or 0.02 per cent) the number of cubic feet of air needed for one hour, = 3,000.
Therefore, a room with a space of 3,000 cubic feet, occupied by one average adult at rest, will not reach its maximum of impurity (that is, the air in such a room will not be in need of a change) before one hour has elapsed.
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The relative quantity of fresh air needed will differ for adults at work and at rest, for children, women, etc. ; it will also differ according to the illu- minant employed, whether oil, candle, gas, etc. — an ordinary 3-foot gas-burner requiring 1,800 cubic feet of air in one hour.
It is not necessary, however, to have 3,000 cubic feet of space for each individual in a room, for the air in the latter can safely be changed at least three times within one hour, thus reducing the air space needed to about 1,000 cubic feet. This change of air or ven- tilation of a room can be accomplished by mechanical means oftener than three times in an hour, but a natural change of more than three times in an hour will or- dinarily create too strong a current of air, and may cause draughts and chills dangerous to health.
In determining the cubic space needed, the height of the room as well as the floor space must be taken into consideration. As a rule the height of a room ought to be in proportion to the floor space, and in ordinary rooms should not exceed fourteen feet, as a height beyond that is of very little advantage.^
Forces of Ventilation. — We now come to the ques- tion of the various modes by which change in the air of a room is possible. Ventilation is natural or
^ In cerebro-spinal meningitis, tuberculosis, and pneumonia, fresh air is curative. Any person, sick or well, cannot have too much fresh air. The windows of sleeping rooms should always be kept open at night. — Editor.
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artificial according to whether artificial or mechanical devices are or are not used. Natural ventilation is only possible because our buildings and houses, their material and construction, are such that numerous apertures and crevices are left for air to come in; for it is evident that if a room were hermetically air- tight, no natural ventilation would be possible.
The properties of air which render both natural and artificial ventilation possible are diffusion, motion, and gravity. These three forces are the natural agents of ventilation.
There is a constant diffusion of gases taking place in the air; this diffusion takes place even through stone and through brick walls. The more porous the material of which the building is constructed, the more readily does diffusion take place. Dampness, plaster- ing, painting, and papering of walls diminish diffusion, however.
The second force in ventilation is the motion of air or winds. This is the most powerful agent of ventilation, for even a slight, imperceptible wind, trav- eling about two miles an hour, is capable, when the windows and doors of a room are open, of changing the air of a room 528 times in one hour. Air passes also through brick and stone walls. The objections to winds as a sole mode of ventilation are their in- constancy and irregularity. When the wind is very slight its ventilating influence is very small; on the other hand, when the wind is strong it cannot be
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utilized as a means of ventilation on account of the air currents being too strong and capable of exerting deleterious effects on health.
The third, the most constant and reliable, and, in fact, principal agent of ventilation is the specific gravity of the air, and the variations in the gravity and consequent pressure which are results of the vari- ations in temperature, humidity, etc. Whenever air is warmer in one place than in another, the warmer air being lighter and the colder air outside being heavier, the latter exerts pressure upon the air in the room, causing the lighter air in the room to escape and be displaced by the heavier air from the outside, thus changing the air in the room. This mode of ven- tilation is always constant and at work, as the very presence of living beings in the room warms the air therein, thus causing a difference from the outside air and effecting change of air from the outside to the inside of the room.
Methods of Ventilation. — The application of these principles of ventilation is said to be accomplished in a natural or an artificial way, according as mechanical means to utilize the forces and properties of air are used or not. But in reality natural ventilation can hardly be said to exist, since dwellings are so con- structed as to guard against exposure and changes of temperature, and are usually equipped with numer- ous appliances for promoting change of air. Win- dows, doors, fireplaces, chimneys, shafts, courts, etc.,
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are all artificial methods of securing ventilation, al- though we usually regard them as means of natural ventilation.
Natural Ventilation — The means employed for ap- plying the properties of diffusion are the materials of construction. A porous material being favorable for diffusion, some such material is placed in several places within the wall, thus favoring change of air. Imper- fect carpenter work is also a help, as the cracks and openings left are favorable for the escape and entrance of air.
Wind, or the motion of air, is utilized either directly, through windows, doors, and other openings ; or indirectly, by producing a partial vacuum in pass- ing over chimneys and shafts, causing suction of the air in them, and the consequent withdrawal of the air from the rooms.
The opening of windows and doors is possible only in warm weather; and as ventilation becomes a problem only in temperate and cold weather, the opening of windows and doors cannot very well be utilized without causing colds, etc. Various methods have therefore been proposed for using windows for the purposes of ventilation without producing forcible currents of air.
The part of the window best fitted for the intro- duction of air is the space between the two sashes, where they meet. The ingress of air is made pos- sible whenever the lower sash is raised or the upper
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one is lowered. In order to prevent cold air from with- out entering through the openings thus made, it has been proposed by Hinkes Bird to fit a block of wood
Fig. 5. HINKES BIRD WINDOW. (Taylor.)
in the lower opening; or else, as in Dr. Keen's ar- rangement, a piece of paper or cloth is used to cover the space left by the lifting or lowering of either or both sashes. Louvers or inclined panes or parts of these may also be used. Parts or entire window panes
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are sometimes wholly removed and replaced by tubes or perforated pieces of zinc, so that air may come in through the apertures. Again, apertures for inlets and outlets may be made directly in the walls of the rooms. These openings are filled in with porous bricks or with specially made bricks (like Ellison's conical bricks), or boxes provided with several openings. A very useful apparatus of this kind is the so-called Sherringham valve, which consists of an iron box fitted into the wall, the front of the box facing the room having an iron valve hinged along its lower edge,
Fig. 6. ELLISON'S AIR INLETS. (Knight.)
and so constructed that it can be opened or be closed at will to let a current of air pass upward. Another very good apparatus of this kind is the Tobin ven- tilator, consisting of horizontal tubes let through the walls, the outer ends open to the air, but the inner
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ends projecting into the room, where they are joined by vertical tubes carried up five feet or more from
Fig. 7. SHERINGHAM VALVE. (Taylor.)
the floor, thus allowing the outside air to enter up- wardly into the room. This plan is also adapted for
Fig. 8. THE TOBIN VENTILATOR. (Knight.)
filtering and cleaning the incoming air by placing cloth or other material across the lumen of the hori-
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zontal tubes to intercept dust, etc. McKinnell's ven- tilator is also a useful method of ventilation, especially of underground rooms.
To assist the action of winds over the tops of shafts and chimneys, various cowls have been devised.
Fig. 9. McKINNELL'S VENTILATOR. (Taylor.)
These cowls are arranged so as to help aspirate the air from the tubes and chimneys, and prevent a down draught.
The same inlets and outlets which are made to utilize winds may also be used for the ventilation effected by the motion of air due to difference in the specific gravity of outside and inside air. Any arti- ficial warming of the air in the room, whether by illuminants or by the various methods of heating rooms, will aid in ventilating it, the chimneys acting
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as powerful means of removal for the warmer air. Various methods have also been proposed for utilizing the chimney, even when no stoves, etc., are connected with it, by placing a gaslight within the chimney to cause an up draught and consequent aspiration of the air of the room through it.
The question of the number, relative size, and posi- tion of the inlets and outlets is a very important one,
6UN BURNER
Fig. 10. VENTILATING THROUGH CHIMNEY. (Knight.)
but we can here give only an epitome of the require- ments.
The inlet and outlet openings should be about twenty-four inches square per head. Inlet openings should be short, easily cleaned, sufficient in number to insure a proper distribution of air; should be pro- tected from heat, provided with valves so as to regu- late the inflow of air, and, if possible, should be placed
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so as to allow the air passing through them to be warmed before entering the room.^ Outlet openings should be placed near the ceiling, should be straight and smooth, and, if possible, should be heated so as to make the air therein warmer, thus preventing a
Fig. II. COWL VENTILATOR.
(Knight.)
down draught, as is frequently the case when the out- lets become inlets.
Artificial Ventilation. — Artificial ventilation is ac- complished either by aspirating the air from the build- ing, known as the vacuum or extraction method, or by
* These outlets may be placed close to a chimney or heating pipes. Warm air rises and thus will be forced out, allowing cool fresh air to enter at the inlets. — Editor.
Ventilation
forcing into the building air from without; this is known as the plenum or propulsion method.
The extraction of the air in a building is done by means of heat, by warming the air in chimneys or
Fig. 12. AN AIR PROPELLER.
special tubes, or by mechanical means with screws or fans run by steam or electricity; these screws or fans revolve and aspirate the air of the rooms, and thus cause pure air to enter.
The propelling method of ventilation is carried out 158
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by mechanical means only, air being forced in from the outside by fans, screws, bellows, etc.
Artificial ventilation is applicable only where a large volume of air is needed, and for large spaces, such as theaters, churches, lecture rooms, etc. For the ordinary building the expense for mechanical con- trivances is too high.
On the whole, ventilation without complex and cumbersome mechanisms is to be preferred.^
* The ordinary dwelling house needs no artificial methods of venti- lation. The opening and closing of windows will supply all necessary regulation in this regard. The temperature of hving rooms should be kept, in general, at 70° F. Almost all rooms for the sick are unfortu- nately overheated. Cool, fresh air is one of the most potent means of curing disease. Overheated rooms are a menace to health. — Editor.
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CHAPTER III Warming
Ventilation and Heating — The subject of the heat- ing of our rooms and houses is very closely allied to that of ventilation, not only because both are a special necessity at the same time of the year, but also be- cause we cannot heat a room without at the same time having to ventilate it by providing an egress for the products of combustion and introducing fresh air to replace the vitiated.
Need of Heating — In a large part of the country, and during the greater period of the year, some mode of artificial heating of rooms is absolutely necessary for our comfort and health. The temperature of the body is 98° to 99° F., and there is a constant radiation of heat due to the cooling of the body surface. If the external temperature is very much below that of the body, and if the low temperature is prolonged, the radiation of heat from the body is too rapid, and colds, pneumonia, etc., result. The temperature essential for the individual varies according to age, constitution, health, environment, occupation, etc. A child, a sick person, or one at rest requires a relatively higher tem-
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perature than a healthy adult at work. The mean tem- perature of a room most conducive to the health of the average person is from 65° to 75° F.
The Three Methods of Heating. — The heating of a room can be accomplished either directly by the rays of the sun or processes of combustion. We thus re- ceive radiant heat, exemplified by that of open fires and grates.
Or, the heating of places can be accomplished by the heat of combustion being conducted through cer- tain materials, like brick walls, tile, stone, and also iron ; this is conductive heat, as afforded by stoves, etc.
Or, the heat is conveyed by means of air, water, or steam from one place to another, as in the hot-water, hot-air, and steam systems of heating; this we call convected heat.
There is no strict line of demarcation differentiat- ing the three methods of heating, as it is possible that a radiant heat may at the same time be conductive as well as convective — as is the case in the Galton fire- place, etc.
Materials of Combustion — The materials of com- bustion are air, wood, coal, oil, and gas. Air is in- dispensable, for, without oxygen, there can be no com- bustion. Wood is used in many places, but is too bulky and expensive. Oil is rarely used as a material of combustion, its principal use being for illumination. Coal is the best and cheapest material for combustion.
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The chief objection against its use is the production of smoke, soot, and of various gases, as CO, C02, etc. Gas is a very good, in fact, the best material for heating, especially if, when used, it is connected with chimneys; otherwise, it is objectionable, as it burns up too much air, vitiates the atmosphere, and the products of combustion are deleterious ; it is also quite expensive. The ideal means of heating is electricity. Chimneys. — AH materials used for combustion yield products more or less injurious to health. Every system of artificially heating houses must therefore have not only means of introducing fresh air to aid in the burning up of the materials, but also an outlet for the vitiated, warmed air, partly charged with the products of combustion. These outlets are provided by chimneys. Chimneys are hollow tubes or shafts built of brick and lined with earthen pipes or other material inside. These tubes begin at the lowest fire- place or connection, and are carried up several feet above the roof. The thickness of a chimney is from four to nine inches; the shape square, rectangular, or, preferably, circular. The diameter of the chimney de- pends upon the size of the house, the number of fire connections, etc. It should be neither too small nor too large. Square chimneys should be twelve to six- teen inches square; circular ones from six to eight inches in diameter for each fire connection. The chim- ney consists of a shaft, or vertical tube, and cowls placed over chimneys on the roof to prevent down
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draughts and the falHng in of foreign bodies. That part of the chimney opening into the fireplace is called the throat.
Smoky Chimneys. — A very frequent cause of com- plaint in a great many houses is the so-called " smoky chimney " ; this is the case when smoke and coal gas escape from the chimney and enter the living rooms. The principal causes of this nuisance are :
(i) A too wide or too narrow diameter of the shafts. A shaft which is too narrow does not let all the smoke escape ; one which is too wide lets the smoke go up only in a part of its diameter, and when the smoke meets a countercurrent of cold air it is liable to be forced back into the rooms.
(2) The throat of the chimney may be too wide, and will hold cold air, preventing the warming of the air in the chimneys and the consequent up draught.
(3) The cowls may be too low or too tight, pre- venting the escape of the smoke.
(4) The brickwork of the chimney may be loose, badly constructed, or broken into by nails, etc., thus allowing smoke to escape therefrom.
(5) The supply of air may be deficient, as when all doors and windows are tightly closed.
(6) The chimney may be obstructed by soot or some foreign material.
(7) The wind above the house may be so strong that its pressure will cause the smoke from the chimney to be forced back.
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(8) If two chimneys rise together from the same house, and one is shorter than the other, the draught of the longer chimney may cause an inversion of the current of air in the lower chimney.
(9) Wet fuel when used will cause smoke by its incomplete combustion.
(10) A chimney without a fire may suck down the smoke from a neighboring chimney; or, if two fire- places in different rooms are connected with the same chimney, the smoke from one room may be drawn into the other.
Methods of Heating. Open Fireplaces and Grates. ■ — Open fireplaces and fires in grates connected with chimneys, and using coal, wood, or gas, are very com- fortable; nevertheless there are weighty objections to them. Firstly, but a very small part of the heat of the material burning is utilized, only about twelve per cent being radiated into the room, the rest going up the chimney. Secondly, the heat of grates and fireplaces is only local, being near the fires and warming only that part of the person exposed to it, leaving the other parts of the room and person cold. Thirdly, the burn- ing of open fires necessitates a great supply of air, and causes powerful draughts.
The open fireplace can, however, be greatly im- proved by surrounding its back and sides by an air space, in which air can be warmed and conveyed into the upper part of the room; and if a special air inlet is provided for supplying the fire with fresh air to be
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warmed, we get a very valuable means of heating. These principles are embodied in the Franklin and Gal- ton grates. A great many other grates have been suggested, and put on the market, but the principal
Fig. 13. A GALTON GRATE. (Tracy.)
objection to them is their complexity and expense, making their use a luxury not attainable by the masses. Stoves. — Stoves are closed receptacles in which fuel is burned, and the heat produced is radiated toward the persons, etc., near them, and also conducted,
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through the iron or other materials of which the stoves are made, to surrounding objects. In stoves seventy- five per cent of the fuel burned is utilized. They are made of brick, tile, and cast or wrought iron.
Brick stoves^ and stoves made of tile, are exten- sively used in some European countries, as Russia, Germany, Sweden, etc.; they are made of slow-con- ducting material, and give a very equable, efficient, and cheap heat, although their ventilating power is very small.
Iron is used very extensively because it is a very good conductor of heat, and can be made into very convenient forms. Iron stoves, however, often become superheated, dry up, and sometimes bum the air around them, and produce certain deleterious gases during combustion. When the fire is confined in a clay fire box, and the stove is not overheated, a good supply of fresh air being provided and a vessel of water placed on the stove to reduce the dryness of the air, iron stoves are quite efficient.
.Hot-air Warming. — In small houses the warming of the various rooms and halls can be accomplished by placing the stove or furnace in the cellar, heating a large quantity of air and conveying it through proper tubes to the rooms and places to be warmed. The points to be observed in a proper and efficient hot-air heating system are the following:
(i) The furnace must be of a proper size in pro- portion to the area of space to be warmed. (2) The
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joints and parts of the furnace must be gas-tight. (3) The furnace should be placed on the cold side of the
Fig. 14.
A HOT-AIR FURNACE.
The cold air from outside comes to the COLD-AIR INTAKE through the cold-air duct, enters the furnace from beneath, and is heated by passing around the FIRE POT and the annular combustion chamber above. It then goes through pipes to the various registers throughout the house. The coal is burnt in the fire pot, the gases are consumed in the combustion chamber above, while the heat eventually passes into the SMOKE FLUE. The WATER PAN supplies moisture to the air.
house, and provision made to prevent cellar air from being drawn up into the cold-air box of the furnace. (4) The air for the supply of the furnace must be
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gotten from outside, and the source must be pure, above the ground level, and free from contamination of any kind.^ (5) The cold-air box and ducts must be clean, protected against the entrance of vermin, etc., and easily cleaned. (6) The air should not be overheated. (7) The hot-air flues or tubes must be short, direct, circular, and covered with asbestos or some other non- conducting material.
Hot-water System. — The principles of hot-water heating are very simple. Given a circuit of pipes filled with water, on heating the lower part of the circuit the water, becoming warmer, will rise, circulate, and heat the pipes in which it is contained, thus warming the air in contact with the pipes. The lower part of the circuit of pipe begins in the furnace or heater, and the other parts of the circuit are conducted through the various rooms and halls throughout the house to the uppermost story. The pipes need not be straight all through ; hence, to secure a larger area for heating, they are convoluted within the furnace, and also in the rooms, where the convoluted pipes are called radi- ators. The water may be warmed by the low- or high- pressure system; in the latter, pipes of small diameter may be employed ; while in the former, pipes of a large diameter will be required. The character, etc., of the boilers, furnace, pipes, etc., cannot be gone into here.
* Great care should be taken that the air box is not placed in con- taminated soil or where it may become filled with stagnant or polluted water. — Editor.
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Steam-heating System. — The principle of steam heating does not differ from that of the hot-water system. Here the pressure is greater and steam is em- ployed instead of water. The steam gives a greater degree of heat, but the pipes must be stronger and able to withstand the pressure. There are also combina- tions of steam and hot-water heating. For large houses either steam or hot-water heating is the best means of warming, and, if properly constructed and cared for, quite healthy.^
* See chapter XI for practical notes on cost of installation of these three conveyed systems — ^hot-air, hot-water, and steam. — Editor.
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CHAPTER IV Disposal of Sewage
Waste Products. — There is a large amount of waste products in human and social economy. The products of combustion, such as ashes, cinders, etc.; the products of street sweepings and waste from houses, as dust, rubbish, paper, etc.; the waste from various trades; the waste from kitchens, e. g., scraps of food, etc.; the waste water from the cleansing processes of individuals, domestic animals, clothing, etc. ; and, finally, the excreta — urine and faeces — of man and animals; all these are waste products that cannot be left undisposed of, more especially in cities, and wherever a large number of people congregate. All waste products are classified into three distinct groups: (i) refuse, (2) garbage, and (3) sewage.
The amount of refuse and garbage in cities is quite considerable; in Manhattan, alone, the dry refuse amounts to 1,000,000 tons a year, and that of gar- bage to 175,000 tons per year. A large percentage of the dry refuse and garbage is valuable from a com- mercial standpoint, and could be utilized, with proper facilities for collection and separation. The disposal of refuse and garbage has not as yet been satisfac-
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torily dealt with. The modes of waste disposal in the United States are: (i) dumping into the sea; (2) filling in made land, or plowing into lands; (3) cre- mation and (4) reduction by various processes, and the products utilized.
Sewage. — By sewage we mean the waste and effete human matter and excreta — the urine and faeces of human beings and the urine of domestic animals (the faeces of horses, etc., has great commercial value, and is usually collected separately and disposed of for fertilizing purposes).
The amount of excreta per person has been esti- mated (Frankland) as 3 ounces of solid and 40 ounces of fluid per day, or about 30 tons of sohd and 100,000 gallons of fluid for each 1,000 persons per year.
In sparsely populated districts the removal and ultimate disposal of sewage presents no difliculties; it is returned to the soil, which, as we know, is capable of purifying, disintegrating, and assimilating quite a large amount of organic matter. But when the number of inhabitants to the square mile in- creases, and the population becomes as dense as it is in some towns and cities, the disposal of the human waste products becomes a question of vast impor- tance, and the proper, as well as the immediate and final, disposal of sewage becomes a serious sanitary problem.
It is evident that sewage must be removed in a 171
Disposal of Sewage
thorough manner, otherwise it would endanger the
lives and health of the people.
The dangers of sewage to health are:
(i) From its offensive odors, which, while not
always directly dangerous to health, often produce
headaches, nausea, etc.
(2) The organic matter contained in sewage de- composes and eliminates gases and other products of decomposition.
(3) Sewage may contain a large number of pathogenic bacteria (typhoid, dysentery, cholera, etc.).
(4) Contamination of the soil^, ground water, and air by percolation of sewage.
The problem of sewage disposal is twofold: (i) immediate, viz., the need of not allowing sewage to remain too long on the premises, and its imme- diate removal beyond the limits of the city; and (2) the final disposition of the sewage, after its removal from the cities, etc.
Modes of Ultimate Disposal of Sewage. — The chief constituents of sewage are organic matter, min- eral salts, nitrogenous substances, potash, and phos- phoric acid. Fresh-mixed excrementitious matter has an acid reaction, but within twelve to twenty hours it becomes alkaline, because of the free ammonia formed in it. Sewage rapidly decomposes, evolving organic and fetid matters, ammonium sulphide, sulphureted and carbureted hydrogen, etc., besides teeming with
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animal and bacterial life. A great many of the sub- stances contained in sewage are valuable as fertilizers of soil.
The systems of final disposal of sewage are as follows:
(i) Discharge into seas, lakes, and rivers.
(2) Cremation.
(3) Physical and chemical precipitation.
(4) Intermittent filtration.
(5) Land irrigation.
(6) " Bacterial " methods.
Discharge into Waters, — The easiest way to dis- pose of sewage is to let it flow into the sea or other running water course. The objections to sewage dis- charging into the rivers and lakes near cities, and especially such lakes and rivers as supply water to the municipaUties, are obvious. But as water can purify a great amount of sewage, this method is still in vogue in certain places, although it is to be hoped that it will in the near future be superseded by more proper methods. The objection against discharging into seas is the operation of the tides, which cause a backflow and overflow of sewage from the pipes. This backflow is remedied by the following methods: (i) providing tidal flap valves, permitting the out- flow of sewage, but preventing the inflow of sea water; (2) discharging the sewage intermittently, only during low tide; and (3) providing a constant outflow by means of steam-power pressure.
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Cremation. — Another method of getting rid of the sewage without attempting to utilize it is by cre- mation. The Hquid portion of the sewage is allowed to drain and discharge into water courses, and the more or less solid residues are collected and cre- mated in suitable crematories.
Precipitation. — This method consists in separating the solid matters from the sewage by precipitation by physical or chemical processes, the liquid being allowed to drain into rivers and other waters, and the precipitated solids utilized for certain purposes. The precipitation is done either by straining the sew- age, collecting it into tanks, and letting it subside, when the Hquid is drawn off and the solids remain at the bottom of the tanks, a rather unsatisfactory method; or, by chemical processes, precipitating the sewage by chemical means, and utilizing the products of such precipitation. The chemical agents by which precipitation is accomplished are many and various; among them are lime, alum, iron perchloride, phos- phates, etc.
Intermittent Filtration. — Sewage may be purified mechanically and chemically by method of intermit- tent filtration by passing it through filter beds of gravel, sand, coke, cinders, or any such materials. Intermittent filtration has passed beyond the experi- mental stage and has been adopted already by a number of cities where such a method of sewage dis- posal seems to answer all purposes.
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Land Irrigation. — In this method the organic and other useful portions of sewage are utiHzed for irri- gating land, to improve garden and other