In the absence of special attention to preventive medicine new truth is forced to fight its way, sometimes for generations, before it is accepted by the medical profession. So strong are the traditions of that profession and so difficult is it for the unconventional or heterodox individual to retain the confidence of conservative patients, that the forces of honorable medical practice tend to discourage research and invention. The man who discovers a surgical appliance is forced by the ethics of his profession either to commercialize it and lose his professional standing, or to abide the convenience of his colleagues and their learned organizations in testing it. Rather than be branded a quack, charlatan, or crank, the physician keeps silent as to convictions which do not conform to the text-books. Many a life-saving, health-promoting discovery which ought to be taken up and incorporated into general practice from one end of the country to the other, and which should be made a part of the minimum standard of medical practice and medical agreement, must wait twenty-five or fifty years for recognition. [Illustration: THE DISCIPLE OF FRESH AIR AND HOME INSTRUCTION IS STILL AN OUTCAST IN SCORES OF HOSPITALS] For want of a school of preventive medicine to emphasize universally every new truth, the medical colleges are permitted to remain twenty-five or fifty years behind absolutely demonstrated facts as to medical truth and medical practice. In 1761 a German physician, Avenbruger, after discovering that different sounds revealed diseased tissue, used "chest tapping" in the diagnosis of lung trouble. In 1815 Leannec discovered that sound from the chest was more distinct through a paper horn. On that principle the modern stethoscope is built. He made an accurate diagnosis of tuberculosis, and while suffering from that disease treated himself as a living clinical study. In 1857 Pasteur proved the presence of germs "without which no putrefaction, no fermentation, no decay of tissue takes place." In 1884 Trudeau started the first out-of-door care of pulmonary tuberculosis in America. In 1892 Biggs secured the compulsory notification of pulmonary tuberculosis. In 1904 began our first out-of-door sea-air treatment for bone tuberculosis. Yet there are thousands of physicians to-day who sincerely believe that they are earning their fees, who, from houses shut up like ovens, give advice to patients for treatment of tuberculosis, who prescribe alcohol and drugs, who diagnose the disease as malaria for fear patients will be scared, who oppose compulsory registration, and who never look for the tuberculous origin of crippled children. Just think of its being possible, in 1908, for a tuberculous young man of thirty to pay five dollars a day to a sanatorium whose chief reliance is six doses of drugs a day!