This is based upon the alleged specific properties of iodoform as being peculiarly fatal to tubercle bacilli, presumably by liberation of free iodine. A cavity to be thus treated should be first emptied as completely as possible, after which may be thrown into it a glycerin emulsion or an ethereal solution, or a suspension in sterilized oil of 5 to 10 per cent. of iodoform. From 25 to 200 Cc. of some such preparation is introduced, while the walls of the abscess are more or less manipulated in the endeavor to completely disseminate the mixture. The cannula through which it has been introduced is then withdrawn; and this can usually be done with but little unpleasant iodoform effect. This is due to the pyophylactic membrane, which limits the activity of the drug as it has done that of the previous contents of the abscess. Such cavities have also been treated by washing out through a trocar with an injection of various antiseptic or stimulating solutions, among which may be mentioned hydrogen peroxide, weak iodine solutions, etc. My own advice is to treat all tuberculous lesions radically when such measures are not contra-indicated by their multiplicity or by too great depression of the patient, and so long as lesions are accessible to ordinary operative procedures. This same advice pertains also to those which have already spontaneously evacuated themselves, or where the overlying skin is threatening to break and permit escape of contents. Almost any case where this is imminent is one in which the surgeon, as such, ought to interfere. On the other hand, in deep collections and in debilitated individuals the treatment by injection may be tried. The best way to treat accessible tuberculous lesions is by extirpation, as this hastens convalescence and leads to more permanent results. THE GUMMAS OF TUBERCULOSIS. The other and essential characteristic of tuberculous disease is the _infectious granuloma_ to which it gives rise. This is a term first applied by Virchow to new formations of granulation tissue which are the result of the presence of invading and specific irritants. This tissue varies little in type from that already described under Ulcers, and is common to the neoplasms which are found in tuberculosis, syphilis, leprosy, glanders, and other local infections. So little does the tissue type vary in these different instances that it is difficult to distinguish by microscopic sections of the unstained tissues, or at least those unstained for bacteria, to which class of lesions they belong. [Illustration: PLATE VII Lupus of Skin. (Gaylord.) _a_, fresh tubercles containing numerous plasma cells; _b_, mature tubercle with giant cells. Below are accumulations of plasma cells about the vessels. Low power. Unna’s polychrome methylene blue.]