Within about a decade of the close of the century, Robert Koch, whose discoveries and ingenious studies in bacteriology had brought him world-wide renown, announced that he had produced a derivative of the tubercle bacillus, which he termed tuberculin, that he thought might prove curative of tuberculous disease. It was to be injected beneath the skin. If the subject was really tuberculous, he would "react" by manifesting a certain degree of fever, and repeated injections would bring about elimination of the tuberculous deposits and thus effect a cure. The world was carried away with such an announcement coming from such a man, and it was thoroughly believed that at last "the great white plague," consumption, was to be conquered. Tuberculin did, indeed, cure certain minor forms of tuberculous disease, such as the skin affection known as lupus, but it soon became evident that it was almost impotent in the treatment of pulmonary consumption. It has, however, served to enable the veterinarian to make out the existence of tuberculous disease in cattle at an early stage of its course, and it is probable that by the slaughter of cattle thus found to be tuberculous much infection of human beings has been prevented. Tuberculin failed of its prime purpose, but it does seem to have marked the initiative of a campaign against consumption which has already proved of incalculable benefit, and bids fair to put that omnipresent disease toward the foot of the list of causes of death. We have made substantial advances in our knowledge of the disease, and we no longer regard it as incurable. We have learned that it is communicable from one person to another, but also that its communication can easily be prevented, so that there is no reason to shrink from association with tuberculous persons. We have learned, too, that consumption in one's progenitors, immediate or remote, hardly makes it even probable that he himself is doomed to suffer with it; the only tuberculous heredity that we now recognize is that of defective ability to withstand the infection, and even this we regard as in most instances readily surmountable. We have learned, furthermore, that pulmonary tuberculous disease is by no means so fatal as it was formerly esteemed, for men whose business it is to make great numbers of post-mortem examinations, such as coroners' physicians and hospital pathologists, assure us that in a very large percentage of cases of death from other causes they find indubitable signs of past tuberculous disease of the lungs which had ceased its activity--been, in fact, cured, either spontaneously or by medical intervention. Such intervention, it has been abundantly proved, is altogether likely to be successful if it is of the right sort and employed early. There is, to be sure, no cure-all. Powerful as the climatic treatment is, it must be supplemented by measures accurately adapted to the individual case, and failure to comprehend this fact