

ACID-FAST SUBSTANCE 375 



those consuming it. Rosenbach's tuberculin is prepared 

 by growing the tubercle bacillus with the ringworm 

 organism, Friedmann's is derived from a turtle tubercle 

 bacillus. Other tuberculins are also on the market, and 

 any tuberculin may be prepared with a human or with a 

 bovine strain of bacillus. 



Chemical products. The tubercle bacillus produces no 

 extra-cellular toxin. Crookshank and Herroun obtained 

 from glycerin broth cultures a proteose and an alkaloidal 

 body. The proteose was also obtained from " perlsucht." 

 Both the alkaloid and the proteose (from both sources) 

 produced a rise of temperature in tuberculous guinea-pigs, 

 while in healthy animals the former caused a slight, and 

 the latter a marked, fall in temperature. 



De Schweinitz and Dorset described chemical products 

 isolated from a special glycerin-asparagin culture medium. 

 From the bacilli themselves an acid body was isolated, 

 probably teraconic acid, an unsaturated fatty acid. A 

 certain amount of the same body was also obtained from 

 the special culture medium, but only a trace from glycerin 

 broth cultures, not because it was not formed in the latter, 

 but because of the difficulty of isolation. This acid 

 seemed to produce on injection depression of temperature 

 and necrosis of the tissues locally, possessed some immu- 

 nising power, and may be the substance producing casea- 

 tion in the tuberculous nodules. The bacilli extracted 

 with hot water yielded an albuminoid, which gave the 

 tuberculin reaction. This they regard as the fever- 

 producing substance. 



Bulloch and Macleod 1 state that the acid-fast substance 

 of the tubercle bacillus is an alcohol. Hot xylol will 

 remove this substance from the tubercle bacillus, and 

 ether or 5 per cent, caustic soda that from the smegma 

 bacillus ; the organisms after this treatment are no longer 



1 Journ. of Hygiene, vol. iv, 1904, p. 1. 



