122 PROTEIN POISONS 



and even vomiting were occasionally noted. After a period 

 of discomfort varying from six to ten hours, during which 

 the patient often complained of dull pain in the various 

 joints, recovery would rapidly and completely take place. 



On examining the powder obtained in this manner 

 microscopically we found that it consisted of colon bacilli 

 which still retained their morphological characteristics and 

 could still be stained by aniline dyes. On the other hand 

 cultures made from this powder have, of course, never 

 given a growth. In other words, the bacillus has not been 

 broken up by this treatment, but simply has been deprived 

 of life and of the power of reproduction. It is worthy of 

 note that neither by the action of alcohol, ether, physiological 

 salt solution, distilled water, nor any simple solvent have 

 we been able to extract a poison from the colon bacillus. 

 Nor, again, can a poison be split off by the action of heat 

 even when the germ substance is heated to 184 C. in a 

 sealed tube for thirty minutes. It is only when we make 

 use of agents which will chemically break up the colon 

 bacillus that we are enabled to obtain a poison apart from 

 the rest of the cellular substance. The powdered bacterial 

 substance is not soluble, but can be held in suspension in 

 normal salt solution and, since it can be boiled without 

 appreciably affecting its toxicity, suspensions were always 

 heated to 100 for fifteen minutes before injection in order 

 to insure sterility. 



This coarsely powdered cellular substance killed guinea- 

 pigs when injected intraperitoneally in doses of 1 to 40,000, 

 body weight, and invariably proved fatal within twelve 

 hours, usually causing death at the end of from six to eight 

 hours. On the injection of a fatal dose of the cellular 

 substance intraperitoneally, we noticed that the most 

 marked change was in the length of the period of incu- 

 bation. Thus, whereas in the case of the living germ from 

 eight to twelve hours passed before noticeable symptoms 

 appeared, in that of the dead germ substance the animal 

 almost invariably showed symptoms of illness at the end 

 of four hours. In regard to the character of these symptoms 



