The illicit sexual relation is the chief though not the only factor in the dissemination of the two serious venereal diseases; so prevalent are these in our large cities that at least half the adult male population of all social grades, according to conservative estimates, contract one or both of them. (In Germany gonorrhoea is the most frequent of all diseases, with the single exception of measles; in America it is about as frequent.) Were the evil effects of these diseases limited to those who seek clandestine indulgence, discussion of this distasteful topic might be reserved for them only; but since he who has acquired either of these diseases is, for an indefinite period, a possible source of contagion to his associates--especially to his bride and her children--the essential facts should be understood by every adult. These facts, so far as they concern the public welfare, are here briefly summarized: 1. Every prostitute, public or private, acquires venereal disease sooner or later; hence all of them are diseased some of the time, and some of them practically all of the time. The man who patronizes them risks his health at every exposure. 2. Medical inspection is an advantage to the prostitute chiefly because it gives her patron a false sense of security. Even the most elaborate and painstaking examination--and such is not bestowed upon the prostitute--may fail to detect a woman's lurking infectiousness; the perfunctory, routine examination actually made affords but a feeble protection to the patron. Moreover, at the first cohabitation after such examination she may acquire disease which she may transmit to every subsequent patron, until it is perhaps discovered at the next examination. 3. The many antiseptic washes, lotions and injections upon which the ignorant rely for protection from disease, are inefficient; not because they cannot destroy the germs of disease, but because they do not penetrate the skin and mucous membranes in which these germs have been sheltered. 4. Gonorrhoea in the male, while usually cured without apparent loss of health, has always serious possibilities; it kills about one in two hundred; it permanently maims one in a hundred; it impairs the sexual power and fertility of a much larger number; it often produces urethral stricture, which later may cause loss of health and even of life; and in many cases it causes chronic pain and distress in the sexual organs, with severe mental annoyance and depression. The loss of health, time and money entailed by these sequels and their treatment may far exceed that occasioned by the original disease. The prevalent notion among the uninformed that gonorrhoea is a mere annoyance, "no worse than a cold," is based entirely upon lamentable misapprehension.