416 CHOLERA. 



on agar, killed by exposure to the vapour of chloroform, 

 when injected intraperitoneally into a guinea-pig, may 

 cause death in from eight to twelve hours. There is 

 extreme collapse, sometimes clonic spasms occur, and the 

 temperature may fall below 30 C. before death. Pfeiffer 

 considers that the toxic substances are contained in the 

 bodies of the organisms, that is, they are intracellular, and 

 that they are only set free by the disintegration of the latter. 

 This opinion is grounded chiefly on the fact that when 

 bouillon cultures were filtered, he found that the filtrate 

 possessed very feeble toxic properties. The dead cultures 

 administered by the mouth produce no effect unless the 

 intestinal epithelium is injured, in which case poisoning 

 may result. He considers that the desquamation of the 

 epithelium is an essential factor in the production of the 

 phenomena of the disease in the human subject. Pfeiffer 

 found that the toxic bodies were to a great extent destroyed 

 at 60 C., but even after heating at 100 C. a small pro- 

 portion of toxine remained, which had the same physio- 

 logical action. 



On the other hand, other observers (Petri, Ransom, 

 Klein, and others), have obtained toxic bodies from 

 filtered cultures. Recently Metchnikoff, E. Roux, and 

 Taurelli-Salimbeni have demonstrated the formation of 

 diffusible toxic bodies in fluid media in the following 

 manner. Small collodion sacs were prepared, each con- 

 taining 2 to 4 c.c. of bouillon. One sac was inoculated 

 with a living virulent culture of the cholera vibrio ; to the 

 second, two entire cultures on agar of the same organism 

 were added, the cultures being first killed by chloroform. 

 Each sac was then closed and placed with aseptic pre- 

 cautions in the peritoneum of a guinea-pig. The animal 

 which received the sac containing the living vibrios soon 

 showed symptoms of choleraic poisoning, and died in a few 

 days, whilst the animal which received the sac containing 

 large quantities of dead organisms showed only transitory 

 symptoms of illness. These observers therefore concluded 

 that toxic substances are formed by the living organisms, 



