408 CHOLERA 



transmitted to others by a natural mode of infection. In this affection 

 of young rabbits many of the symptoms of cholera are present. The 

 organisms occur in large numbers in the intestine, and in some cases a 

 few may be found in the blood, and especially in the gall bladder. Many 

 of these experiments were performed with the vibrio of Massowah, which 

 is now admitted not to be a true cholera organism, others with a 

 cholera vibrio obtained from the water of the Seine. 



It will be seen from the above account that the evidence 

 obtained from experiments on intestinal infection of animals, 

 though by no means sufficient to establish the specific relation- 

 ship of the cholera organism, is on the whole favourable to this 

 view, especially when it is borne in mind that animals do not in 

 natural conditions suffer from the disease. 



Experiments performed by direct inoculation also supply 

 interesting facts. Intraperitoneal injection in guinea-pigs is 

 followed by general symptoms of illness, the most prominent 

 being distension of the abdomen, subnormal temperature, and, 

 ultimately, profound collapse. There is peritoneal effusion, 

 which may be comparatively clear, or may be somewhat turbid 

 and contain flakes of lymph, according to the stage at which 

 death takes place. 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. 360). These and 

 other 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 pronounced. Hence arise questions as 

 to the nature and mode of action of toxic bodies produced by 

 the cholera organism. 



Toxins. 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 on agar, 



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

 now known (as mentioned above) not to be a true cholera organism. This fact 

 shows that the effects described are not specific to the latter. 



