+Repression of Prostitution.+--By the moral prophylaxis of syphilis is meant the cultivation of such moral ideals as will contribute to the control of a disease which is so closely associated with sexual irregularities. Since public and secret prostitution serve as the principal agencies for the dissemination of the disease, it follows that anything tending to decrease the amount of disease in prostitutes, on the one hand, or to diminish the amount of promiscuous sexual activity, on the other, will retard the spread of syphilis. Systems based on the first ideas, aiming rather to control the disease in public women by inspection of their health and activities than by suppressing prostitution, have failed because the methods of control ordinarily practised are worthless for the detection of infectiousness. So-called regulation has, therefore, given way very largely in progressive communities to the second ideal of repressing or abolishing the outward evidences of vice as far as possible. In behalf of sanitary control of prostitution, leaving out of the question its moral aspect, it must be admitted that Neisser, probably the greatest authority on the sexual diseases, believed that, as far as syphilis is concerned, the use of salvarsan as a means of preventing infection from prostitutes has never had a satisfactory trial. In behalf of abolition it would seem that systematic stamping-out of the outward evidences of vice, the making of immorality less attractive and conspicuous, is, in theory at least, a valuable means of diminishing the extent and availability of an important source of infection. +Educational Influences.+--To do something positive against an evil is certainly a more promising mode of attack than to use only the negative force of repression of temptation. Education of public opinion offers us just such a positive mode of attack. Men and women and boys and girls should first be taught sexual self-control even before being made aware of the risk they run in throwing aside the conventional moral code. Teach honor first and prudence next. The slogan of education in sexual self-restraint is the easiest to utter and the most difficult to put into practice of all the schemes for the control of sexual diseases. A large part of the difficulty of making education effective arises from one or two situations which are worth thinking over.