THE SPLIT PRODUCTS OF TUBERCLE BACILLUS 169 



this body upon both normal and tuberculous animals; it 

 has nothing to recommend it. What is true of the cell 

 poison is equally true of the precipitate poison and the 

 final filtrate. The effects of these poisons on animals are 

 harmful only harmful. 



The Effects of the Cell Residue on Animals. This is the 

 non-poisonous group obtained by splitting up the cellular 

 substance with alkali in absolute alcohol. On healthy 

 animals it has no recognizable ill effect, either in single or 

 repeated doses, either large or small. In this product we 

 see the one small ray of hope of finding, among the split 

 products, a body that may possibly be of service in the 

 treatment of incipient and localized tuberculosis. Before 

 giving the basis of this slight hope we will tell what we have 

 done with this product. 



In the first place, it sensitizes guinea-pigs to the tubercle 

 bacillus. The following are illustrations: Guinea-pig No. 

 199, weight 530 grams, received, December 20, 50 mg. of 

 the residue. Thirteen days later it had intra-abdominally a 

 large loop of the avirulent culture (the same amount given 

 to pigs 159, 163, and 151, see p. 167). This injection was 

 made at 11.30 A.M. At 12 M. the temperature had fallen 

 to 96 F. At 2.30 P.M. it was 97.1, and at 5 P.M. it was 

 99, and the animal was apparently well. 



Pig No. 200, weight 530 grams, received 50 mg. of the 

 residue intra-abdominally. Thirteen days later it had 

 intra-abdominally one large loop of the avirulent culture. 

 The rectal temperature before the injection was 101 F. 

 Within half an hour it had fallen one degree, but went no 

 lower and the animal seemed to be but little disturbed. 

 We have similar records of other animals. 



We compare these results with those recorded of animals 

 159, 163, and 151, and tentatively conclude that the sensi- 

 tizing agent in the cellular substance is the portion that 

 we have designated as the residue. But the avirulent 

 bacilli killed the animals sensitized with the cellular sub- 

 stance because when the bacteriolytic ferment was set 

 free or activated by the second injection, it split up not 



