It is now certain that tuberculin has entered our materia medica to remain. Not only is it being used for diagnostic purposes, but it is also gaining ground, slowly but surely, as a therapeutic agent in the treatment of tuberculosis in all of its forms and manifestations. There is hardly a sanatorium for the treatment of tuberculosis where it is not considered the diagnostic agent par excellence in obscure cases, and in many sanatoriums it is used for immunizing purposes. All this is due to the fact that the action of tuberculin has been carefully observed, so that its great potency has been appreciated, and doses that some eighteen years ago would have been scoffed at as homeopathic, if employed as initial doses, are now considered dangerous.
Pulmonary tuberculosis is now being treated with tuberculin, and, owing to cautious use, almost, but not entirely, without