BACTERIAL CELLULAR SUBSTANCE 43 



given subcutaneously no longer killed but 2 mg. did. Of 

 the part that was dissolved in the acid pepsin solution, 

 doses up to 100 mg. had no effect. A like result was obtained 

 with the cellular substance of the typhoid bacillus. The 

 amount of cellular substance left undigested after three 

 days' exposure to the acid-pepsin was about 10 per cent, of 

 that originally taken. The conclusion is that the gastric 

 juice slowly digests the bacterial cellular proteins, and in 

 so doing destroys the poison. 



With trypsin the effect is somewhat different. The 

 cellular protein goes into solution more rapidly, and at 

 least a part of the poison goes into solution without complete 

 loss of its properties. The parts of both the colon and 

 typhoid cellular substance that passed into solution after 

 three exposures to trypsin killed in doses of from 35 to 40 

 mg. given intra-abdominally, while the undigested portion 

 killed in doses of from 4 to 7.5 mg. 



One gram of the cellular substance given to a rabbit 

 through a stomach-tube had no recognizable effect on the 

 animal. 



At one time early in these investigations we had an idea 

 that the poison in the colon cell resisted peptic digestion, 

 and we therefore quite naturally suspected that it might 

 be a nuclein. This belief was founded upon the following: 

 The growth on fifty Roux flasks was removed, extracted 

 with 96 per cent, alcohol so long as the alcohol took up 

 coloring matter, then dried, placed in a beaker, and stirred 

 with 1 liter of 0.2 per cent, hydrochloric acid dilution in 

 which 0.5 grams of active pepsin had been dissolved. The 

 beaker with content was kept in the incubator for two 

 days, with occasional stirring. The undigested portion 

 on microscopic examination was found to be amorphous, 

 but still easily stained with methylene blue. It was col- 

 lected on a filter, washed thoroughly with 96 per cent, 

 alcohol, dried at 100, and pulverized. One hundred milli- 

 grams of this powder was shaken with 50 c.c. of water, 

 forming an acid, colloidal mixture. On adding sodium 

 bicarbonate to a faintly alkaline reaction, the substance 



