On the one hand are those who direct their efforts toward the annihilation of the tubercle bacillus. We are sufficiently instructed about the life history and habits of this organism to lay our plans upon a firm, scientific basis—a basis so firm and at first sight so simple and so plausible that over-enthusiasm led to predictions that have been sadly disappointed. The principles are sound indeed, but in practice their application has met with insuperable difficulties. These obstructions have sharpened our wits to find new avenues that now promise a more ready approach to the goal. To put the matter briefly, the tuberculosis campaign of the past fifteen years has taught us two important lessons: first, that the tuberculous cannot be isolated in their homes; second, that they cannot be cured in or out of sanatoria. I am shocked myself to read these bald statements, particularly the second, and still I am convinced that they are true. Some patients can be isolated in their homes, and many patients recover from tuberculosis and remain well. Tuberculosis is very amenable to treatment and under proper conditions the results of treatment are very gratifying. The difficulty is that the proper conditions are in most instances wanting, and when they are absent sanatorium recovery is almost invariably followed, after a brief period, by relapse. The records of cases with tubercle bacilli in the sputum establish this fact. Concerning the value of statistics of cases without tubercle bacilli in the sputum I entertain the gravest doubt. While I am heartily in favour of treating such patients, the personal equation enters too largely into the diagnosis to give the results convincing value as evidence of the lasting benefits of treatment. Experience has taught me that the educational value of sanatoria has been grossly exaggerated, and that this value is of small account in a broad plan of prevention. Our present knowledge, fortified by the costly experience of the past fifteen years, forces us to believe that the most direct and effective way of dealing with the tubercle bacillus is to isolate as many advanced consumptives as is possible. The hospital, perhaps supplemented by colonies, is the rational method of procedure. Other factors are of importance; all other factors are, but this is the fundamental and essential factor in the campaign.