small membership in 1872, this Association has now grown to be one of the largest and most influential of our national societies. It was organized for the mutual benefit and co-operation of health officers and others who are thinkers and workers in the field of preventive medicine. Its constitution states that its objects "shall be the advancement of sanitary science and the promotion of organizations and measures for the practical application of public hygiene." It has done good work in the diffusion of knowledge, by providing an audience for those who have made researches into the causes of diseases and the best means of avoiding or preventing them, as well as in urging upon the authorities the importance of sanitary legisla tion. Little interest was manifested in its meetings until the epidemic of 1878, when the public became suddenly aware of the importance of its deliberations and conclusions. Every subject that can possibly be suggested in the vast field of sanitary research receives careful attention, and the reports and papers that are presented at the meetings, together with the discussions that follow, are printed annually, and form a series of volumes containing not only much that is valuable, but also, it is to be regretted, giving space to much that is worthless.

Aiming at the same general work of educating the masses, several of the State Boards of Health have adopted the plan of holding sanitary conventions, or councils, in various towns throughout the State, at intervals during the year, where topics relating to State medicine are freely discussed. In speaking of the conventions in that State, the Secretary of the Michigan Board of Health, in his report for 1882, says: "Their good effects are apparent in the after-results in the towns where such conventions are held. In most instances the citizens are aroused to the necessity of establishing and maintaining an effective board of health; more efficient measures are taken for the suppression of outbreaks of contagious diseases; a better understanding of the necessity for cleanliness, good sewerage, and good ventilation prevails; the relations between the people and the health authorities are more cordial, and a stronger support is given to the health officer in his effort to administer the public health laws."

Measures for the control of contagious diseases have been introduced by most of the boards, with marked success in many instances. The cases, when found, are immediately isolated, and, if possible, placed in temporary hospital structures. As the result of its experience in dealing with this class of disease, the New York State Board of Health in 1882 distributed to local boards through the State a circular giving directions for procedure in cases of epidemics, with diagrams for the erection of temporary hospitals. In the city of New York both small-pox and typhus fever are now considered to be under perfect control. The methods adopted in that city for dealing with these scourges is to isolate a case as soon as discovered, disinfect the premises where it has been found and closely watch all suspicious persons till the period of incubation has passed. Owing to these measures a threatened epidemic of typhus fever last spring was promptly brought under control.

The subject of vaccination has received a great deal of attention of late, and scarcely a report from a board of health fails to devote space to it, showing that the prejudice that still exists against it in some minds is gradually being removed. It is still, however, a mooted question whether vaccination should be made compulsory or not. Some States, such as Illinois and New York, require public-school children to be vaccinated before entrance, and certificates are given if the operation has been successful, without which a child cannot enter a school. Considerable success

has attended the methods pursued in New York City. The Board of Health of that city employs a corps of inspectors, whose duty it is to visit every tenement-house and public school twice during the year, examining each child, and offering free vaccination to every one in the tenements. From October 1, 1874, when this work was begun, to July 1, 1883, there have been 130,598 primary, and 452,550 re-vaccinations, making a total of 583,148 operations performed by this corps. The records that are kept by the Department show that about ninety-five per cent. of the primary, and about sixty per cent. of the re-vaccinations are successful, and that protection from small-pox is assured in every case. The great numbers of immigrants that are constantly passing through the city make the mortality returns for the year much higher than they would otherwise be, as the cases of small-pox are confined to this class of the population, the older inhabitants that have been successfully vaccinated experiencing complete immunity from the disease.

The pollution of rivers in this country has not yet received the attention it deserves. Special reports have been made from time to time, but they, as a rule, cover only the case of the stream under litigation, when riparian or other rights are infringed, and have no bearing on the general subject.

Food and drug adulteration has received much attention, and four States have passed laws for its prevention. Nothing more, however, than a passing notice of the work in this direction is necessary, as the subject is treated at length in one of the articles that follow.

Many of our older cities have sewerage systems that seem to have been the result of chance instead of prearranged and carefully studied method. Flat-bottomed sewers, covered watercourses, and badly constructed oval sewers, which have been aptly described as elongated cesspools," are, in some instances, the only means for removing the sewage from the vicinity of dwellings. Cesspools are still in use in many cities, towns, and villages, but are fast disappearing under the vigorous measures of boards of health. Too much cannot be said against their use under any circumstances. The almost depopulation of the city of Memphis, in 1878, is a terrible example of the loss of life that may be occasioned by their use. Much more attention is now, however, being paid to systematic sewerage; new towns are employing competent engineers to prepare plans for its proper disposal, and old ones are seeking advice for the improvement of their existing systems. There has been some controversy of late on the comparative merits of what are termed the "combined and "separate" systems, the former providing for the removal of both sewage and rainfall through one set of pipes, and the latter requiring a separate system for each. No hard-and-fast rules can, however, be given for the employment of either system; local considerations and future wants should, in all cases, determine the use of either, or a combination of both.

Within the past few years the problem of how to remove house waste in suburban districts has been solved by the employment of a system of subsurface irrigation. The efficiency, simplicity, and comparative cheapness of this mode of sewage disposal makes it available for small plots of ground, and at the same time has none of the dangers of the old system of leaching cesspools.

Although the condition of our public schools is beginning to receive official attention, and the grosser sanitary evils remedied, there is yet comparatively little interest taken in such matters by the public at large. Much has been done, and is being done; but those who recognize the evils of

imperfect heating and lighting, uncomfortable seats, defective plumbing and ventilation, crowded rooms, climbing stairs, badly constructed and dirty closets, impure water, etc., are often sadly hampered in their efforts at reform by causes that are very well put by Mr. Warren R. Briggs, in a recent report of the Michigan State Board of Health, who classifies them as follows: 1, The stereotyped school-house is always before them (the advocates of a better system), and is usually taken as a model for the new building; 2, Local prejudice against sanitary reform-the ancient inhabitant classes it with all the modern crazes and new-fangled notions; 3, Penurious and short-sighted economy in the appropriation of small sums for the construction of buildings; 4, The difficulty of obtaining satisfactory data. This last class has, in a great measure, been removed by competi tion for prizes offered by the editor of the Sanitary Engineer for the best plans for school buildings, which, by directing the attention of architects and others to the matter, has now made it possible to obtain plans for schools of varying size, admirable in construction and ingenious in arrangement.

Municipal boards of health have not been behind, and in some instances have led, the State boards in their work of sanitary reform. The New York City Board was the first to organize, and being the pioneer in municipal hygiene has borne the brunt of the battle against ignorance. Its methods have been closely watched, and many of its regulations adopted by other cities.

Another competition, also originating with the Sanitary Engineer, was opened in December, 1878, and a prize of $500 was offered "for the best four designs for a house for workingmen, in which might be secured a proper distribution of light and pure air, with an arrangement of rooms that would yield a rental sufficient to pay a fair interest on the investment." This competition attracted great attention, and so aroused the public to the evils of the then tenement-house system that "an amendment to the Tenement-House Act was passed by the State Legislature, May, 1879, limiting the space to be occupied by any tenement-house to sixty-five per cent. of the lot it occupies, requiring all bedrooms to have windows, with direct light and air, and greatly adding to the powers of the Board of Health to remedy abuses in such buildings."

A very important move was made in 1881, when the State legislature passed a law requiring the registration of all plumbers in New York and Brooklyn, and giving the municipal board of health the power to make such rules as it might think proper for the regulation of the plumbing and drainage in all buildings to be erected subsequent to the first day of October of that year. Plans must be submitted to the Board for approval, and powers were given it to compel compliance with the rules and regulations by making the violation of them a misdemeanor. These rules embody the very best and latest practice in such matters, and their enforcement has already greatly improved the sanitary condition of the city. Inspectors are employed to examine periodically each building in course of erection, and to report any violation of the plans submitted to and approved by the Board. From October 1, 1881, to October 16, 1883, plans for 4,489 buildings have been submitted. These figures will not, of course, agree with the records of the Building Department, as they represent only those houses that contain plumbing, and therefore come under the jurisdiction of the Board of Health. Of these 4,489 buildings 2,808 were tenement-houses, with accommodation for 133,473 persons. The beneficial effects of the "plumbing law" cannot be accurately measured till the lapse of several years has made the collection of statistics possible;

but the providing of over a quarter of a million of people with healthy homes has undoubtedly already improved the condition of the city, a result that will be more and more apparent, as the years pass, in the gradual lowering of its death-rate.

Following the lead of New York, several other cities have adopted similar plumbing laws, the enforcement of which is, in every instance, accompanied with the like good results.

In 1880 the Health Commissioners of Chicago were authorized to inspect the factories of that city, and since that time great improvement has been made in their management and condition, by preventing injuries to employés from moving machinery; by the removal of injurious dust and vapors; by providing proper ventilation for workrooms, and means of escape in case of fire; and by improving the condition of the plumbing and drainage.

The above sketch will, it is hoped, give the reader some idea of the work that has been done, and is still being done, in this country in the department of preventive medicine. The success that has attended the labors of State and local boards of health and of volunteer associations, especially within the past few years, shows a constantly increasing knowledge of sanitary matters among the people generally, which every physician and scientific man should strive to direct in proper channels by all the means in his power. There are, it is true, some few individuals who, by wild and unwarranted statements of the dangers to health from various causes, attempt to make capital by the excitement they create. These, however, together with those who still ridicule sanitary reform as a newfangled notion, must surely give way before the honest and legitimate. labor of trained scientists. It must be admitted that the horizon is still dark in most of the States; but with the tremendous strides made by the nation in other directions, the time cannot be far distant when Sanitary Science shall be given its proper place throughout the length and breadth of the land.

In conclusion, the editor wishes to express his obligations to those who have been associated with him in the preparation of this Supplement for the articles they have contributed, and on which articles the work is dependent for its value.

F. N. O.

WATER.

BY ELWYN WALLER, PH.D.,

Chemist to the Health Department of New York City.

Necessity for Water.-It is impossible to over-estimate the sanitary importance of water for the welfare and comfort of man. For the preservation of a proper degree of cleanliness of our persons, our clothes, our dwellings, or the articles with which we have to come in contact, it is indispensable.

As regards our food, it must be remarked that about 73 per cent. of the human body consists of water, and the food proper to nourish one should contain about 81.5 per cent. of water. What is termed solid food" contains, roughly speaking, from 50 to 80 per cent. of water, and thus to make up the necessary amount of water, some must be drunk as water, or in some beverage of which water is the chief constituent. A healthy man weighing 11 stone (154 b) requires every twenty-four hours about 5 pints of water in some form or other. When the amount of water in the system is diminished by about one per cent. of the whole, the sensation of thirst is felt, which we usually allay by imbibing the needful amount.'

In brief, water is a prime necessity for human beings, both externally for cleanliness, and internally as food.

Sources of Water.-The water which we require in our daily life and avocations, comes to us more or less directly from the clouds, as rain or

snow.

The rain water may be collected directly as it falls, or it may soak into the earth and flow forth again as springs, forming eventually ponds, streams, or rivers, or it may penetrate deeper and require us to dig wells in which it may collect.

Our sources of supply may therefore be classified as Rain water, Surface water (including springs, ponds, streams, rivers), and Well waters.

From none of these sources, however, can we obtain water which is chemically pure (i. e., nothing other than the compound of oxygen and hydrogen known under that name), because water is the great solvent in nature and dissolves some of every substance, gaseous or solid, with which it may come in contact. Many of these substances are beneficial, most of them are harmless, while some are not only hurtful, but may even be deadly.

Term "Impurity."-In speaking of those substances dissolved by natural water many persons, no doubt following the lead of chemists, call them all "impurities," which is correct in the sense that they are not water; while sanitarians frequently use the term impurities to designate only those sub

1

1 Church, Plain Words about Water. Pamphlet. London, 1877.