1. Further Studies of the Biological Methods for the Diagnosis of Tuberculosis. J. Bronfen Brenner, M. H. Kahn, J. Rockman, and Max Kahn: There are many difficulties to be surmounted in applying successfully a biological test for the diagnosis of tuberculosis. The peculiar chemical properties of the tubercle bacillus have rendered it a difficult task to get reliable results by means of the complement deviation test, owing to the fact that the preparation of the antigen was fraught with many difficulties. Recently, however, Besredka cultivated the Koch bacillus on an entirely new medium, and he observed that the organism thus grown presented certain properties not usually inherent to the bacillus.
Thus in studying the antigenic properties of his cultures, Besredka found that they may be successfully used for the complement deviation test. Last year we made an extensive study of this subject and, although we found that the complement deviation test with Besredka's tuberculin is very useful in the majority of cases, it had certain properties, which may lead to obtaining nonspecific results.