TUBERCULIN

n. Tu2-busrk'u2l-i2n. A preparation invented by R. Koch and considered by him to be a means of diagnostic at ing and curing tuberculosis. Said by Koch to be an extract made with glycerin of cultures of the tubercle bacillus. It is injected subcutaneously, and is thought to cause destructive inflammation of the ti ue surrounding the tuberculous deposit, whereby the deposit is eliminated, with the production of fever. [B, 270 (a, 38); a, 34.] Crude t. A glycerin extract of the toxic substances present in cultures of the tubercle bacillus in veal broth containing 1 per cent. ' of peptone and 4 or 5 per cent, of glycerin. The culture liquid is evaporated and filtered, [a, 34.] Modified t. Crude t. that has undergone various changes by the precipitation of certain constituents or filtration, or in which the mode of preparation is changed, as in Koch's first modification, in which a precipitate was obtained by adding alcohol to crude t. [a, 34.] [s. 658]