allow in his neighborhood, for sanitary reasons. The best results in summer street-cleaning are obtained by washing or flushing the

streets, for thus the dirt containing germs is prevented from getting into the air. The garbage is removed in carts, and part of it is burned in huge furnaces. The animal and plant refuse is cooked in

Removal of ashes by department of street great tanks; from this cleaning, New York.

material the fats are ex

tracted, and the solid matter is sold for fertilizer. Ashes are used for filling marsh land. Thus the removal of waste matter may pay for itself in a large city.

The Necessity of a Pure Milk and Water Supply. The city of New York is spending hundreds of millions of dollars to bring a supply of pure water to her citizens. Other cities are doing the same. The world has awakened to the necessity of a pure water supply, largely because of the number of epidemics of typhoid which have been caused by contaminated water. Typhoid fever germs live in the food tube, hence the excreta of a typhoid patient will contain large numbers of germs. In a city with a system of sewage such germs might eventually pass from the sewers into a river. Many cities take their water supply directly from rivers, sometimes not far below another large town. Such cities must take many germs into their water supply. Many cities, as Cleveland and Buffalo, take their water from lakes into which their sewage flows. In cities which drain their sewage into rivers and lakes, the question of sewage disposal is a large one, and many cities now have means of disposing of their sewage in some manner as to render it harmless to their neighbors. Filtering such water by means of passing the water through settling basins and sand filters removes about 98 per cent of the germs. The result of drinking unfiltered and filtered water in certain large cities is shown graphically on the following page.

In the country typhoid may be spread by the germs getting into a well or spring from whence the supply of water comes. This

may be avoided by having privies and cesspools some distance from the well and so placed that they will drain away from it. Wells should have a cemented cap around the top so as to keep out surface water, as germs rarely live long more than five feet below ground.

Serious outbreaks of typhoid have been traced to contaminated milk supplies. A case of typhoid exists on a farm; the sewage gets into the well from which water is used for the washing of milk cans. Typhoid germs thrive in milk. Thus the milkman spreads disease. The diagram following illustrates a recent epidemic in Stamford, Conn., which was traced to a farm on which was a person having typhoid.

Growth of bacteria in a drop of impure water allowed to run down a sterilized culture in a dish.

1904

A

1906

1898

B

1901

1892

C

1896

1906

1908

Cases of typhoid per 100,000 inhabitants before filtering water supply (solid) and after (shaded) in A, Watertown, N.Y.; B, Albany, N.Y.; C, Lawrence, Mass.; D, Cincinnati, Ohio. What is the effect of filtering the water supply?

HUNT. ES. BIO.-28

Railroads are often responsible for carrying typhoid and spreading it. It is said that a recent outbreak of typhoid in Scranton, Pa., was due to the fact that the excreta from a typhoid patient traveling in a sleeping car was washed by rain into a reservoir near which the train was passing. Railroads are thus seen to be great

open sewers. Some more sanitary kind of toilet should be used so that filth and disease will not be scattered over the country. he....... h.....

A diagram to show how typhoid may be spread in a city through an infected milk supply. The black spots in the blocks mean cases of typhoid. A, a farm where typhoid exists; the dashes in the streets represent the milk route. B is a second farm which sends part of its milk to A; the milk cans from B are washed at farm A and sent back to B. A few cases of typhoid appear along B's milk route. How do you account for that?

Pure water is the

How the Board of Health fights Typhoid. first essential in preventing epidemics of typhoid. Health board officials are constantly testing the supply, and, if any harmful bacteria are found, a warning is sent out to boil the water. Boiling water at least 10 minutes kills most harmful germs.

The milk supply is also subject to rigid inspection. Milk brought into a city is tested, not only for the amount of cream present to prevent dilution with water, but also for the presence of germs. The cleanliness of the cans, wagons, etc., is also subject to inspection.

"The patients live out of doors."

The cows are also inspected to see if they have tuberculosis, for such cows might spread the disease to human beings.

During the summer months many babies die from cholera infantum. This disease is almost entirely spread through impure milk. Flies are largely responsible for the spread of the disease by carrying the germs to milk. Spread of such diseases through milk can only be prevented by careful pasteurization (heating to 170° for a few minutes). In many large cities pasteurized milk is sold at a reasonable price to poor people, and thus much disease is prevented.

Disease germs of various sorts, typhoid, tuberculosis, pneumonia,

diphtheria, and many others may be transferred through the agency of food. Fruits and vegetables may be carriers of disease, especially if they are sold from exposed stalls or cars and handled by the passers-by. All vegetables, fruits, or raw foods should be carefully washed before using. Spoiled or overripe fruit, as well as meat which is decayed, is swarming with bacteria and should not be used. The board of health has supervision over the sale of fruit, meats, fish, etc., and frequently in large cities food unfit for sale is condemned and destroyed.

Tuberculosis,

How the Board of Health fights Tuberculosis. which a few years ago killed fully one seventh of the people who died from disease in this country, now kills less than one tenth. This decrease has been largely brought about because of the treatment of the disease. Since it has been proved that tuberculosis if taken early enough is curable, by quiet living, good food, and plenty of fresh air and light, we find that numerous sanatoria have come into existence which are supported by private or public means. At these sanatoria the patients live out of doors, especially sleep in the air, while they have plenty of nourishing food and little exercise. In this way and by tenement-house laws which require proper air shafts and window ventilation in dwellings, by laws against spitting in public places, and in other ways the boards of health in our towns and cities are waging war on tuberculosis.

REFERENCE BOOKS

Sharpe, A Laboratory Manual for the Solution of Problems in Biology. American Book Company.

Allen, Civics and Health. Ginn and Company.

Davison, The Human Body and Health.

American Book Company.

Gulick Hygiene Series, Town and City. Ginn and Company.

Hough and Sedgwick, The Human Mechanism. Ginn and Company.
Richman and Wallach, Good Citizenship. American Book Company.
Ritchie, Primer of Sanitation. World Book Company.

REPORTS, ETC.

American Health Magazine.

Annual Report of Department of Health, City of New York (and other cities). Bulletins and Publications of Committee of One Hundred on National Health. School Hygiene, American School Hygiene Association.