THE CLEAVAGE OF PROTEINS WITH ALKALI 103 



The "crude soluble poison" is soluble in strong mineral 

 acids, and such solutions remain clear on being boiled and 

 on dilution with water. However, a few drops of mineral 

 acid added to an aqueous solution cause a precipitate, 

 which seems to indicate that the acidity of the aqueous 

 solution is caused by the presence of some organic acid. 



The poison diffuses slowly through collodion sacs both 

 w r ithin the animal body and when suspended in distilled 

 water. The following experiments bear on this point: 

 Two hundred milligrams of the crude soluble poison from 

 the cellular substance of the typhoid bacillus dissolved in 

 20 c.c. of water was placed in each of two collodion sacs 

 which were then suspended in distilled water. At the 

 end of twenty-four hours, the Millon reaction was given 

 by the dialysate. This was replaced every twenty-four 

 hours by fresh distilled water, and the dialysis continued 

 for ninety-six hours. At the end of this time the combined 

 dialysates were concentrated to dryness, the residues dis- 

 solved in absolute alcohol, filtered, and again evaporated. 

 The brown, sticky residue, thus obtained, dissolved in 

 water, was acid in reaction, had the characteristic odor, 

 and when injected into a guinea-pig, killed in twenty minutes 

 with typical symptoms, thus showing that the poison does 

 diffuse through a collodion sac. So slowly, however, does 

 it diffuse that at the end of ninety-six hours it was not 

 wholly removed from the sac. In another experiment 

 one gram of the same poison in 8 c.c. of water was put into 

 a collodion sac which was introduced into the abdominal 

 cavity of a medium-sized rabbit. After twelve days, the 

 animal not being visibly affected, the sac was removed 

 and found to contain 6 c.c. of a clear fluid which looked 

 more like blood serum than anything else. Five cubic 

 centimeters of this injected into the abdomen of a guinea- 

 pig had no effect. We conclude from this that the poison 

 had diffused from the sac, but so slowly that it was disposed 

 of by the animal's body without recognizable discomfort. 



Notwithstanding the ready solubility of the crude soluble 

 poison in absolute alcohol, we must regard it as either 



