It is usually considered futile to attempt to defeat the devil with his own methods, because he knows so much better how to use them. But abuse does not do away with use, and the success of quacks in reaching the people demands our respect. There is no reason why their methods, based on a knowledge of human nature and human psychology, should not be employed to appeal to needs rather than to weaknesses. A good thing may lie unused because of lack of advertisement. Vitality is coming to be the passion of the American people. It is on this sincere passion that fakirs have so long traded. There can be no doubt that advertisements of health-promoting goods are quite as profitable as health advertisements that injure health, when equally effective methods are used to make them reach the public. The tradition has been repeatedly mentioned in this book that the better the doctor, the less he advertises himself, except in medical and scientific journals that notoriously fail to reach the people. The same is too often true of reputable remedies and goods. The theory that these things stand or fall on their merits is not borne out by practical experience,--conspicuously in the case of "fake" remedies. Purely philanthropic undertakings for the advancement of health fail, if not placed before the people whom they aim to help in an attractive, convincing form. Failure to advertise a worthy cause limits its usefulness, and is therefore unjustifiable, whether we speak of medicine, legal aid, or dental clinics. An intensive study of the methods used to advertise patent medicines will suggest means of extending the usefulness of health-promoting goods. Aside from clever methods of suggestion that lead many people to take medicine for imaginary ailments, especially seasonal ailments, patent-remedy advertisers have employed (as an argument for the efficiency of their cures) scientific theory, bacterial origin of diseases, recent medical or physiological discoveries, and state and national movements for promoting health. In fact, they have turned to their own uses the very law that seeks to control them and the exposures that seek to exterminate them. Whatever may be the merits of Castoria, the "Don't Poison Baby" advertisement on the following page, printed just after the accompanying "Babies Killed by Patent Medicines," which appeared in a home journal, was surely a clever bit of advertising. Upon an editorial in a daily paper on the relation of eyeglasses to headache and indigestion, an optician based a promise of immediate relief for these ailments if he himself were patronized. The recent investigations of the Department of Agriculture, and of Professors Chittenden and Fisher, in regard to foodstuffs, are proving helpful to food quacks and advertisers of pills for constipation and indigestion. Since the passage of the Pure Food Law one health food is advertised in a column headed "Pure Food."