SOCIAL, or PUBLIC, HYGIENE, the science of caring for the physical well being of entire communities, as simple hygiene is the science of guarding the physical welfare of the individual against disease. Obviously the former is more than the latter on a larger scale, for the living together of large numbers of people creates dangers that do not necessarily threaten the individual. It is only within recent years that social hygiene has af fected the public policies of municipali ties or states, but its importance is of the highest order, since it is due to the application of the laws of social hygiene that the fatal epidemics of the earlier periods of history have been banished. What were commonly known as plagues in olden times were, in the light of mod ern science, nothing but such dirt dis eases as smallpox and malarial fevers, none of which can flourish where the pre cautions dictated by a knowledge of hy giene are applied. To a lesser degree the same may be said of all contagious dis eases. The rules of hygiene are chiefly based on the knowledge that most con tagious diseases are caused by foul air, which, first of all, robs the body of the vitality which, in good health, enables it to throw off the attacks of disease germs; by filth and dampness, in which the dis ease germs are incubated; and the va rious methods by which these germs are transmitted from their places of incuba tion to the vulnerable parts of the human body. Social hygiene, therefore, as en forced through state laws and municipal ordinances, demands the removal of all filth; clean streets, removal of garbage and proper disposal of sewage; a certain minimum amount of air space per in dividual in human dwellings, with proper ventilation, as illustrated in the tenement house laws of large cities; careful in spection of sources of food and water supply, that infection may not be carried by this medium; and, finally, when sick ness has made its appearance, measures for the segregation of those already af fected. The abolition of public drinking
cups is another illustration of the pre cautions against disease demanded by modern social hygiene. The result of not enforcing laws and ordinances in this field may be witnessed in the present condition of the large cities of Russia, where, in some cases, epidemics have reduced the populations by a third. Dur ing the World War the United States Federal Government became especially interested in social hygiene, on account of the precautions that had to be taken against epidemics in the mobilization camps. The greatest enemy here encoun tered, however, was found to be venereal diseases. As a consequence of what was learned by investigation during this pe riod, the Federal Government has decided to continue its activities in this field on a permanent basis. The agencies through which it works are: The United States Public Health Service, the Inter-Depart mental Social Hygiene Board and Army and Navy Departments. These first be gan to function in the summer of 1918. The second of these institutions, created by an Act of Congress, passed July 9, 1918, received an appropriation of four million dollars. As a result of the ac tivities of these Government institutions, 96 laws were passed in 1919, in various States to protect society against venereal diseases. During 1919 all these institu tions together treated 35,000 cases.