Public Hygiene.—A very great part of the work of public sanitary officers consists in the prevention of the specific inf(. 'Ions and con tagious diseases which are 11 to become epidemic in a community, and s the majority of these are -now believed to be due to micro organisms, the efforts of health officials are largely directed to measures which will either, prevent their introduction or dissemination or wibl make the surroundings unfavorable for their development, or will destroy their vitality if they are present. The present methods of quarantine or maritime inspection, of isolation of cases of contagious disease, and of disinfec tion, are based mainly upon the results of bac teriological research, and differ in many respects from those in force a generation ago. The greater the number of persons residing within a limited area, the greater is the need for a general system of sanitary regulations which will prevent individuals from causing or spread ing disease, and will secure to each one pure water and air. The greater part of public hygiene, therefore, may be said to be municipal hygiene, and the problems which present them selves to city and town authorities in regard to it are numerous and complicated. It includes general climatic conditions, soil under human habitations, the character of the latter and their cleansing, the disposal of refuse and excreta, and the cleansing• of streets.
Climatic conditions cannot to any extent be modified: they must be neutralized, when in sanitary, by other conditions pertaining to hygiene. All nations have. more or less adapted their habits to their climate, unless acclimated so that they become part of its working: the hours of work or travel, the character of dwellings, the sites, the diet found wholesome by experiment, all form part of a hygienic sys tem built up by social experience and tradition. Those unacclimated may have personal advice from predecessors; too often nothing but pes sonal experience can be of any avail, and fre quently that is only acquired by fatal results.
The subject of dwellings includes a number of considerations. The site, if possible, should not be one where the ground water is near the surface, or freshets or tides set back the drain age of closets, or where there are great fluctua tions in the level of the ground water, which it is better to have nearer the surface and steady than lower and more unstable. Filled-in land in cities is often unhealthful, but tenants cannot in practice exercise much choice; the city au thorities should prevent bad results by thorough sewerage with a good fall. The construction most important to have right is the plumbing, including the drains at the bottom; it is a commonplace which need not be dwelt on, that leaking sewer pipes and clogged drainage mean the infection of a house with disease-laden air. Paint is better than paper for walls, as it can be washed; and old paper should be scraped off before new is laid on. When possible rooms should be large enough not to need incessant change of air; when not possible, as is usual in cities, plenty of windows and the fullest pos sibilities of draft should make up; if this, too, is not available, the best systems of artificial ventilation. Unhappily, science is very back ward in this class of invention, and small close, unventilated rooms shorten millions of lives and prematurely break down working power in even the civilized cities of the world. The normal supply should be at least 3,000 cubic feet of air per head each hour, and this largely in creased in work or sickness. The volume of consumption and other scrofulous diseases, bronchitis, pneumonia, etc., is directly dependent on foul air, which also increases the virulence of all zymotic diseases. The ventilation of public buildings rests on the same principles. and has the same result. The warming of houses is of great importance, and is generally ill done, with disregard of ventilation. The vast majority of houses in America are over heated even when the air-supply is enough, giv in a sensitive skin which very readily cold?' The water-supply is a matter of public concern: where there is a flat price, people do not stint themselves. Where there are meters, they often do; but toilets should be kept fully flushed at any cost. In country houses, where city water and sewerage are not available, it is necessary to insist oti the frequent cleaning and disinfection of receptacles for excreta. Ad vice on this point is obtainable gratis from phy sicians, public health officers and others. If the dry methods are carefully used, they have many advantages in healthfulness over the elaborate city systems.
Personal Hygiene.— This has very many divisions: the most obvious are considerations of food, and drink, nerve stimuli, clothing, cleanliness, natural necessities, work and rest, and moral self-control. In the matter of diet,
there can be no one rule: "at forty?' says the proverb, Bone is either a fool or a physician*; and each must use his own experience as a guide to whether meat is a necessity or vege tarianism an advantage, what foods agree with him, whether dry meals give him heartburn or drinking with them impedes digestion, and whether he is eating so much as to make him heavy, impairing his• capacity for work and enjoyment, or making his body gross. In gen eral, probably professional and sedentary work ers as a class over-eat, and would find their minds more alert and their bodies freer from disorders with less gratification of appetite. Nerve stimuli, ranging from tea, coffee and cocoa, tobacco, alcoholic drinks and opium, are hard to frame a general rule upon ; they, too, have infinitely varied effects. Cocoa is largely a food; coffee with most is an agree able stimulant, with many an active nerve poison, producing heavy headaches and incipient stupor; tea is a real nerve food on occasion and in small quantity, while taken steadily and largely it is a poison and a very mischievous one; tobacco sparingly used by grown men probably does little harm, and sometimes saves worse things, but should not be used by those under age, nor by those with weak nerves, and is highly injurious in heart disease, Bright's disease, and veneral diseases; alcoholic drinks suggest too many questions for discussion here; narcotics like opium, hashish, etc., as well as chloral and its like, should be used only on a physician's prescription. Clothing, if there is time and means, can be accommodated to changes of weather and occasion so as greatly to advance health; with most, there must be a rough average. Personal cleanliness within limits is a sine qua non of reasonable immunity from disease, and with delicate persons, of rea sonably good ordinary health; but even this good thing .can be irrationally overused and made mischievous. Too frequent hot baths in a northern climate are a great aggravator of lung-diseases, and one great city (Pittsburgh) had a marked decrease of pulmonary complaints one winter when the water-supply broke down, and people resorted greatly to dry rubbing. Especially it is possible to use too much soap, and keep the natural oil of the skin washed away. Natural necessities should be attended to more constantly than they are: workmen especially often grudge the time, but the wait ing till there is severe pressure often creates dangerous bladder and intestinal complaints. Work, for most, is not under their own control; but to some extent resting is, and the average American perhaps owes more to compulsory public holidays than he is aware. There is more temptation to overwork than to idle, for the average man. Exercise should be taken by the sedentary, even a homespun housemethod being preferable to nothing. Grotius preserved his health in prison by whipping a top two hours a day. This should be one of the most rigidly imposed forms of self-control, which in all forms is all-important. Excessive sexuality, either of act or imagination, is simply destruc tive of will-power as well as bodily fibre; giving way to fits of anger or despondency is almost a recipe for entire nervous wreck. As to laziness, of mind or body, it is one of the worst and most incurable forms of this evil.
The management of children is really per sonal hygiene, only controlled by another than the subject; the care of the dead belongs to pub lic hygiene; the prevention of disease belongs either to medicine, by the use of drugs like quinine or inoculations, or to house-hygiene as disinfection. The hygiene of the sick-room should be under the direction of the physician.
See BACTERIOLOGY; BATH; DRESS; COOKERY; DIETETICS; DISINFECTION; EXERCISE, PHYSI CAL; EDUCATIONAL ATHLETICS; HOSPITALS; NURSING; PLUMBING; SANITARY SCIENCE AND PUBLIC HEALTH; WATERS, CITY, DISPOSAL OF; VENTILATION ; HYGIENE, MILITARY ; MILITARY SANITATION ; WATER-SUPPLY.
Bergey, D. H., 'The Prin ciples of Hygiene> (4th ed., Philadelphia 1912) • Harrington, Charles, 'Practical Hygiene' (4th ed., Philadelphia 19111; Daniels and Alcock, 'Tropical Medicine and Hygiene> (London 1911) ; Parkes and Kenwood, 'Hygiene and Public Health' (Philadelphia 1914); 'Encyclo pedie d'Hygiene et de midecine publique' (Paris 1892) ; Rubner, 'Lehrbuch der Hygiene' (Leipzig 1891) ; Rohe, G. H., and Robin, A., 'Text-Book of Hygiene) (4th ed., Philadelphia 1908) ; Price, G. M., 'Hygiene and Public Health> (Philadelphia 1910); Pyle, W. L, 'Manual of Personal Hygiene' (ib. 1812); Sedgwick, W. T., 'Sanitary Science and the Public Health' (New York 1902).