ROFESSOR Finkelnburg, of Bonn, estimates that the average length of human life in the sixteenth century was only between eighteen and twenty years, and at the close of the eighteenth century it was a little over thirty years, while to-day it varies in different countries from less than twentyfive to more than fifty years. The span of life since 1880 has been lengthened in civilized countries over eight years. No two factors have contributed so much to the general results as the improvement of the air we breathe and the water we drink. Indeed, we have ample evidence that with the introduction of pure-water supplies and sewers the general mortality in numerous cities during the past fifty years has been reduced fully one half, the good effects being especially shown by a marked decrease in the number of deaths from typhoid fever, diarrheal diseases, and consumption.

The death rate in the city of New York from 1850 to 1854 was 38 per 1,000, while in 1911, in spite of the density of population, it was 15.2 per 1,000, which means a saving of something over 50,000 lives each year in that city alone.

The mortality in the registration area in the United States has declined from 18.6 per 1,000 in 1880 to 15 in 1910, which means a saving of something over 300,000 lives a year in the country at large.

The reduction in the death rate from typhoid fever since 1880 amounts to 41.90 per cent., the death rate from consumption has decreased 48 per cent and

the mortality from diphtheria and croup during the same period has been reduced 80.40 per cent; the mortality from diarrheal diseases in children under two years of age in many communities also shows marked decreases. These results are the direct outcome of preventive medicine, and are as gratifying as they are striking.

Influence of Water Supplies upon Typhoid Fever Death Rates.

It has long since been known that rivers are always purer near their source, the amount of impurities increases as we descend the stream, because the water courses are the natural drainage channels of the country, and the wastes of human life and occupations find their way into the streams. It is also well known that our large American rivers are the sewers and at the same time the source of water supply for nearly all the cities located on their banks. These cities show, moreover, a marked prevalence of typhoid fever, thus confirming what has been observed over and over again, that this disease, as also cholera, dysentery, and diarrheal diseases, can be carried from one town or city to another by means of inland water ways. Indeed, the question is one of extreme interest even to the residents along the Great Lakes; we know that large cities like Buffalo, Erie, Cleveland, Detroit, and Milwaukee discharge their sewage into the lakes, and we also know how some of these cities, notably Chicago and Cleveland, suffered from typhoid fever visitations by contaminating their own water supplies. It is also a well-known fact that many of the cities were obliged to resort to purification of their water

The rates for cities using unpurified river water fluctuated from 33.1 at Minneapolis to 122.1 at Pittsburg, while Philadelphia and Cincinnati had a rate between 50 and 60.

It is gratifying to report that, according to the Journal of the American Medical Association May 31, 1913, a great reduction has occurred in the typhoid death rate of these cities as a result of purification of their water supplies; the

rate for Minneapolis in 1912 was 11.5; Pittsburg, 12.7; Philadelphia, 12.5; and Cincinnati, 7.5.

These statistics, in spite of the many other factors concerned in the dissemination of typhoid fever, conclusively show that the water supply plays the most important role in the spread of the disease.

The writer's estimate is that about 80 per cent of the cases of typhoid fever are water and milk borne, and about 20 per cent may be spread by the agency of flies, personal contact, bacillus carriers, the consumption of raw oysters and shell fish raised in sewage polluted waters, or

the eating of strawberries, radishes, celery, and other vegetables and fruits which have been contaminated with infected night soil.

In the White House address, the writer presented charts and tables showing that since 1881 the death rate from typhoid fever had fallen in fourteen countries and cities from an average of 42.3 to 18.1 per 100,000 of population, a reduction. of 54.3 per cent. He also presented a chart showing the effect of change in water supply on typhoid fever death rates in seven American cities.

The average annual typhoid death rate before the change was 69.4, and after the substitution of a pure supply it fell to 19.8 per 100,000, a reduction of 70.5 per cent.

It has been urged that improved methods of medical treatment are responsible for a considerable reduction in the death rates from typhoid fever, but when we see such a striking change immediately after the installation of filtration plants, as in the case of Albany, Lawrence, Philadelphia, Pittsburg, and Cincinnati, for example, we are forced to the conclusion that the substitution of a pure supply for a previously contaminated one plays the most important role by diminishing primarily the number of cases.

The Hygienic Value of Pure Water.

According to the census of 1900, there were 35,379 deaths from typhoid fever in the United States during that year, and, based on an estimated mortality of 10 per cent, it is within reason to assume a yearly prevalence of 353,790 cases of this disease. If we calculate the average cost for care, treatment, and loss of work to be $300, and the average value of a human life at $5,000, we have a total loss in the United States of $283,032,000 from one of the so-called preventable diseases. In 1902 I wrote, "Reduce the prevalence of the disease one half, which has been accomplished in Europe, and can be done here, and the question of hygienic value of pure water will be answered from an economic point of view."

We have no similar returns for the whole of the United States for the census year of 1910, but the number of deaths from typhoid fever in the regis

tration area which covers 58.3 per cent of the entire population was 12,673, equivalent to a death rate of 23.5 per 100,000 population, or nearly one third less than the rate shown for the period 1901-1905 (32.2), the rate for 1911 was 21 per 100,000. Bulletin 112 on Mortality Statistics 1911, p. 28, says: "The mortality from this cause in the United States is still far in excess of that of progressive European countries; if it could be reduced by three fourths, so that it would be only 5 per 100,000, as in England and Wales, the Netherlands and Prussia for 1910, it would represent a saving of nearly 10,000 lives at the period of their greatest usefulness as a rule in the registration area alone."

What has been said of typhoid fever is equally true of the other water-borne diseases, because the germs or ova of these diseases are present in the intestinal tracts and presumably also in sewage contaminated water. Mr. Allen Hazen, one of the most distinguished experts on water purification in America, has conclusively shown that as the result of filtration plants in five cities supplied previously with impure water, there was not only a reduction of 81 per cent in the deaths from typhoid fever, but also a marked reduction in the general death rate. His computations clearly indicate that, where one death from typhoid fever has been avoided by the use of a better water, a certain number of deaths, probably two or three, from other causes, have also been avoided. The truth of Hazen's theorem has been confirmed by Professor Sedgwick. It is a difficult matter to explain how water is connected with the deaths other than those from water-borne diseases, yet when we consider that water enters into the composition of the human body to the extent of 60 per cent, we are in a position to appreciate the sanitary acumen of Aristotle when he wrote in his Politics, "The greatest influence on health is exerted by those things which we most freely and frequently require for our existence, and this is especially true of water and air." While much has been accomplished, more remains to be done. Sanitarians have maintained for years that no community or individual has a right to pol

lute streams used for public water supplies any more than a man has to poison his neighbor's well.

One of the most pressing needs is uniformity of legislation and adequate protection of interstate waters, a matter of Federal or even international importance when such pollution affects or threatens to affect the sanitary condition of the people of more than one state, because the individual states are powerless to protect themselves against the misdeeds of their neighbors. The legal aspects of water pollution were presented by Dr. J. L. Leal in a paper read before the American Public Health Association in 1901, and also in a review of the laws forbidding pollution of inland waters in the United States by Edwin B. Goodell. Consult Water Supply and Irrigation Paper No. 152 U. S. Geolog. Survey 1905.

The general importance of the subject is being more and more appreciated, and the North American Conservation Conference in February, 1909, adopted the following resolution in reference to this subject.

"Facts which cannot be questioned demonstrate that immediate action is necessary to prevent further pollution, mainly by sewage of the lakes, rivers, and streams throughout North America. Such pollution, aside from the enormous loss in fertilizing elements entailed thereby, is an immediate and continuous danger to public health, to the health of animals, and when caused by certain. chemical agents to agriculture. Therefore, we recommend that preventive legislation be enacted."

Students of medical sociology have noted with humiliation that we have not kept pace in matters of public health with foreign countries, notably Great Britain, Germany, and France. These countries, in the matter of water protection, not only filter the water, but also prevent river pollution.

Lengthening Human Life.

According to Professor Fisher's Report on "National Vitality" more than 600,000 deaths now occur in the United States which might be prevented, that is postponed, and thus lengthen the average span of human life about fifteen

years, by the application of modern hygiene and sanitation as yet unapplied.

This report, based upon expert opinion, shows that there are constantly about 3,000,000 persons seriously ill in the United States of whom 500,000 are consumptives; that more than half of this illness is preventable, and that the economic gain from mitigation of preventable disease in this country alone would exceed $1,500,000,000 per annum.

While such a statement should be a matter of serious concern to all thoughtful people, we have still greater reason for alarm when we are told by Mr. Rittenhouse, the president of the Provident Savings Life Assurance Company of New York, that the mortality from diseases of the heart, blood vessels, kidneys, apoplexy, and cancer has increaesed in this country over 100 per cent during the past thirty years.

Insanity, according to some authorities, has increased nearly 300 per cent during the past fifty years.

Unfortunately the mystery which surrounds the causes of chronic degenerative diseases, and which carry off over 240,000 victims every year in this country, has not yet been solved. At present it is largely a matter of surmise that this increase is due to wrong habits of life, certain nutritive disturbances resulting from overfeeding, underfeeding, or improperly balanced diet, and possibly the continuous action of toxic substances generated within the body upon the living cells. But we do not yet know the real causes. In a general way, we know that the most frequent causes of insanity are syphilis, alcohol, drug addictions, mental stress, and overwork. We also know that diseases of the heart, blood vessels, liver, kidneys, and of the nervous system may be caused by industrial poisons, and appear especially to go hand in hand. with our ever-increasing "national drink bill."

We have reason to believe that the habitual use of alcohol not only stimulates the proliferation of connective tissues, but also causes degenerative changes by conversion of the albuminoid tissues into fats, and that the so-called vice diseases probably play a very important role in the production of chronic diseases. Our

knowledge, however, is extremely indefinite, and the time has arrived when the Federal government should undertake the solution of these problems. Private philanthropy has done much for the promotion of medical science, but has so far failed to solve the problems under consideration.

State boards of health lack the appropriations necessary to carry on such investigations, and since, in the final analysis the people have to pay the bill, there is no good reason why the Federal government should not undertake such work for the use and benefit of all the people.

Occupational Diseases and Industrial
Accidents.

In addition to the problems referred to, none are more important than the prevention of occupational diseases. Health is the chief asset of the workingman, and no greater calamity can befall him than when his earning capacity is impaired or arrested by reason of sickness or disability. It means in many instances the utter financial ruin of the family, and is doubtless one of the most potent causes of poverty and distress.

Many of the diseases are incident to occupation and environments, and industrial efficiency and earning power can be promoted by appropriate safeguards and adequate protection of the men, women, and children engaged in gainful occupations. It is certainly startling to be told by Mr. Fredk. L. Hoffmann in his monograph on mortality from consumption in dusty trades, that the general death rate. for 1900 in manufacturing and mechanical industries in the United States was 13.8 per 1,000 and the consumption rate 2.6 or 18.8 per cent of the mortality from all causes, while the farming population furnished a consumption rate of only 1.5 or 9.5 per cent of the mortality from all causes. Indeed it is estimated that nearly 70,000 wage earners perish every year from industrial tuberculosis, and that by factory inspection and effective methods for the prevention and removal of dust fully one half of these lives could be saved.

This is not at all speculative, since Professor Röpke in a paper read before the International Congress on Hygiene held