INTRAPERITONEAL INJECTION. 415 



If the dose is large, organisms are found in considerable 

 numbers in the blood and also in the small intestine, but 

 with smaller doses they are practically confined to the 

 peritoneum. Kolle found that when the minimum lethal 

 dose was used in guinea-pigs, the peritoneum might be free 

 from organisms at the time of death, the fatal result having 

 taken place from an intoxication (cf. diphtheria, p. 364). In 

 rabbits, after intravenous injection of comparatively large 

 quantities, death may follow within eighteen hours, with 

 symptoms of general intoxication ; the organisms are 

 present in the blood, though rather diminished in number, 

 and few are to be found in the intestine. If, however, the 

 dose is smaller and the animals live longer, then the 

 organisms may settle and multiply in the intestine, and 

 changes quite analogous to those in cholera are produced 

 congestion of mucous membrane, and at places desqua- 

 mation of epithelium (Issaeff and Kolle). In the case of 

 animals which die when these changes have occurred, the 

 organisms may have quite disappeared from the blood and 

 internal organs. These experiments show that though the 

 organisms undergo a certain amount of multiplication when 

 introduced by the channels mentioned, still the tendency to 

 invade the tissues is not a marked one. On the other 

 hand the symptoms of general intoxication are always pro- 

 nounced. Hence arise questions as to the nature and 

 mode of action of toxic bodies produced by the cholera 

 organism. 



Toxines. Though there is no doubt that there are 

 formed by Koch's spirillum toxic bodies which produce 

 many of the symptoms of cholera, there is at present very 

 little satisfactory knowledge regarding their chemical nature. 

 The following summary may be given. 



It has been shown, especially by R. Pfeiffer, 1 that toxic 

 phenomena can be produced by injection of the dead 

 spirilla into animals. A certain quantity of a young culture 



1 Pfeiffer obtained his earlier results with a vibrio from Massowah, 

 which is now known not to be a true cholera organism. The fact shows 

 that the effects described are not specific to the latter. 



