CONGRESS OF AMERICAN PHYSICIANS AND SUR

GEONS.

Will be held in WASHINGTON, D. C., MAY 4th-6th, 1897President, WILLIAM H. WELCH, M. D., LL. D., Baltimore, Md.

The Association societies represented are as follows:

American Otological Society, President, Dr. Arthur Mathewson, Brooklyn, N. Y.

American Neurological Association, President, Dr. M. Allen Starr, New York City.

American Gynecological Society, President, Dr. J. R. Chadwick, Boston, Mass.

American Dermatological Association, President, Dr. J. C. White, Boston, Mass.

American Laryngological Association, President, Dr. C. H. Knight, New York City.

American Climatological Association, President, Dr. E. F. Ingals, Chicago, Ill.

Association of American Physicians, President, Dr. J. M. DaCosta, Philadelphia, Pa.

American Association of Genito-Urinary Surgeons, President, Dr. F. S. Watson, Boston, Mass.

American Orthopedic Association, President, Dr. Samuel Ketch, New York City.

American Physiological Society, President, Dr. Russell H. Chittenden, New Haven, Conn.

Association of American Anatomists, President, Dr. Frank Baker, Washington, D. C.

American Pediatric Society, President, Dr. S. S. Adams, Washington, D. C.

American Surgical Association, President, Dr. J. C. Warren, Boston, Mass.

American Opthalmological Society, President, Dr. G. C. Harlan, Philadelphia, Pa.

Chairman of the Executive Committee, Landon Carter Gray, M. D., New York City.

Treasurer, Newton M. Shaffer, M. D., New York City.

Secretary, William H. Carmalt, M. D., New Haven, Conn.

THE SANITARIAN.

MAY, 1897.

NUMBER 330.

DANGERS OF SANITARY NEGLECT AT THE WATERSHEDS FROM WHICH COME SUPPLIES OF CITY WATER.*

BY PROF. W. P. MASON, OF RENSSELAER POLYTECHNIC INSTITUTE, TROY, N. Y.

Everybody is talking or writing about water, but the public is far from being well posted. Ocular evidence of purity is popularly sufficient. The bright and limpid water from the well which drains a graveyard is quite satisfactory to those who would shudder over a cholera ship's touching at our most distant port. The $5,000 just voted at Albany, N. Y., for studying the bubonic plague were better expended toward getting a pure water supply for that city.

A letter written me says: "Water taken midway between the surface and bottom of a river will always be found as pure as fresh spring water. Impurities on the surface will be blown ashore in a few hours, while those heavier than the water will sink to the bottom."

Highly desirable as it would be to keep the waters of our great rivers in potable purity, the enormous expense would be prohibitory, apart from considerations of great injustice to established institutions. Large centers of population now in existence turn their sewage directly into the river on whose banks they stand, and an up-stream city might well complain should it be forced at great expense to establish sewage disposal plants when the town below for much less money could secure purer water from some inland source.

A land should be looked upon as watered by its smaller lakes, its springs and brooks, and sewered by its great streams, especially

*Abstract of a recent lecture before the Franklin Institute, Philadelphia.

by its navigable rivers. Its water sources should be protected by law with exceeding care, and no river or stream should be added to its list of drains except after proper consideration by a State Board of Health, followed by legislative permission.

The typhoid fever outbreak at Plymouth, Penn., showed the direct relation between epidemic disease and a polluted water supply. It was traced to a single typhoid patient whose dejecta were thrown out upon the snow upon a hillside at whose base ran the stream supplying the town. The dejecta were frozen solid for weeks; but the March thaws dissolved and carried them into the stream below. Pruden long since showed that typhoid bacilli can survive three months' continuous freezing; while a more recent authority finds germ life standing the temperature of liquid oxygen, 298 degrees below zero, Fahrenheit.

The Massachusetts State Board of Health by a series of experiments at Lawrence, has determined that through intermittent filtration with beds of gravel or sand city sewage may be converted into potable water.

On many a farm and within the limits of many a town, human dejecta are disposed of in a vault or cesspool, and the purifying power of the earth depended upon to prevent pollution of the family well, or of the adjacent stream. The distance from cesspool to well is often so short that the intervening soil has not the capacity to eliminate the amount of filth present, even by a process which must be essentially a continuous rather than an intermittent form of filtration. An elaborate series of analyses of the earth in the immediate vicinity of a cesspool showed that pollution extended to at least fifty feet from the cesspool.

In New York State the occurrence of typhoid fever cases in country, as compared with city, have been in the ratio of 33 to 24. The average annual death-rates for thirteen Massachusetts cities stand, before introduction of public water supply, 79.04 per 100,000; after such introduction, 38.03. For the whole State of Connecticut, the percentage of typhoid deaths to total deaths had fallen from 5.08 in 1870 to 1.84 in 1893. Such figures show the advantage of selecting water supplies over the general run of those derived from the domestic well.

PROPER CARE OF WATERSHEDS.

The proper care of the watershed is as necessary as it is unusual. Such care should extend even to protecting the ground

water for a considerable distance before it enters the feeding brooks of a district.

The larger cities of our country construct aqueducts, conveying the water from collecting to distributing point, under circumstances usually precluding the introduction of sewage material. Such handling is not universal-open channelways are quite commonly seen; and care is not always taken to prevent pollution during the water's flow.

The cholera epidemic at Messina, Sicily, in 1887, lasted from September 10 to October 25, totaling 5,000 cases and 2,200 deaths. The government instituted an examination of the water supply. It left the mountain gathering grounds of excellent quality, but was conveyed to the city in an open conduit, and favoring the Messina washerwomen, who wash outdoors, a portion of the public water was deflected before reaching the wells and taken into neighboring wash pools. A very fair proportion, after having cleansed the soiled linen of the inhabitants, found its way back again into the conduit, and continued its course to the city. Further contamination occurred in the city, the mains being of unglazed tiles, very leaky, with the sewers running frequently atop of the water mains. The government sent tank ships to the mains, filled them with pure water, the people drank thereof, the cholera cases fell immediately from seventy to five. An entirely new and efficient distributive system has since been introduced, and the city has escaped further cholera visitation.

ORIGIN OF TYPHOID FEVER.

Two conceptions of the origin of typhoid fever are held by opposing schools of bacteriologists: That the typhoid germ is always the offspring of a bacillus of its own kind; the other, that the progenitor in question is often a saprophyte, which takes on its pathogenic properties by cultivation through successive generations. under favorable conditions. Army officers view with favor the theory of the saprophytic origin from some germs in the soil. The presence of filth and the production of disease are very closely related.

The public at large have an abiding faith in the efficiency of self-purification of running streams beyond the ability of science to remove. The bacterium does not suffer in efficiency even though the oxygen be reduced greatly below the normal supply. Sedimentation plays a part in general purification during open flow; but it is only a small one.

The sum total of self-purification occurring during the flow of an open stream is so insufficient as to permit of the carriage of infection for many miles toward the sea.

In drawing a water supply from a large lake, sedimentation becomes of prime importance, as the element of time enters very largely into these cases. Sedimentary deposits of polluting materials should not be disturbed after settlement, for they may retain. their objectionable properties long after they have separated from the water levels above them.

In lakes the surface water cools down in autumn, and toward the verge of winter a temperature would be attained increasing its gravity beyond that of the lower layer on which it floated. When this point is reached vertical circulation is established and the lake turned over. With the advent of freezing weather a second stratification would ensue. The warm sun of April would inaugurate a summer stagnation again. It is advisable to avoid drawing the supply from a stagnant layer, especially with the same resting upon a dirty bottom. Clean water, stored in clean reservoirs, must form layers, of course; but the bottom portions may be used as freely as those nearer the surface. When the periodical turnover takes place, the water which has rested upon a dirty bottom starts upon its forward course, diffusing throughout the entire lake materials it has received during its rest. Much plant food is distributed through the upper waters, and the growth and decay of these waters cause the unpleasant taste so often met with in our city supplies.

CLEANING OF STORAGE PONDS.

The cleaning of storage ponds, it has been said, is all a mistake, and that it would be far better to leave the vegetable debris and add to the accumulation rather than diminish it. Comparative experiments upon reservoirs have shown, however, that improved water unquestionably follows cleaning; and it must be remembered that while good water may be obtained from swamp sources, where vigorous growth disposes of the products of decay, beyond question the reverse obtains under conditions permitting the products of decomposition to accumulate. The bottom of a prepared reservoir should be cleaned of all varieties of vegetable matter. Decomposition of recently killed vegetation takes place quite rapidly at first under water, but afterward proceeds with great slow

ness.

A reservoir with gently sloping sides furnishes favorable conditions for contaminated water supply. Such sides permit thin lay