=Statement of the Case.= Pulmonary tuberculosis is a communicable disease, transmitted from person to person by means of the tubercle bacilli contained in the sputum of infected patients, or in the breath expired during paroxysms of coughing. The bacilli thus liberated, find their way into the system of another individual, either through the respiratory or alimentary tract, or both. The enormous prevalence of tuberculosis is due to the fact that its infectious nature was not recognized until 1882 when Koch discovered the bacilli. Since that time it has been classed as a transmissible disease, and during the past ten years a vigorous effort has been made to eradicate it. This agitation is popularly known as the anti-tuberculosis campaign, and associations for the suppression of tuberculosis have sprung up in all parts of the country. So far, no serum or vaccine has been found by which this disease may be controlled, as was the case when smallpox and diphtheria were checked. The sole way of overcoming it is to overcome the ignorance concerning its nature, its transmissibility, and the means by which it is spread. At the beginning of the campaign it was believed that simple education along these lines was all that was needed to obtain results. These results were expected to follow as soon as the patient was informed of the nature of his disease, and how to avoid spreading it, and as soon as those in contact with him were given like information and taught how to avoid infection. Ten years ago, in the optimism of the moment, tuberculosis was freely proclaimed a “curable” disease; so that together with the campaign of prevention went a campaign of teaching the patient how to become a “cured,” or as we now call it, an arrested, case. The mechanics of cure were equally simple—rest, fresh air, and food were all that was needed, provided the disease was taken in the early stages. And all that was necessary for “cure,” just as all that was necessary for prevention, was to tell the patient what to do, and those about him what to do, and the thing was done. This is the theory upon which the work was founded, and in theory this is still a sound principle upon which to continue it. Unfortunately, a series of unlooked for conditions interposed themselves between this theory and our ability to put it into practice. At the time when the crusade was begun these conditions were not recognized, and it is only through long study of the situation, from its social, economic, and legal as well as clinical aspects that we get some idea of the difficulties and complexities of the task before us.