^4 Researches Regarding Cholera : The Blood. J^part I. 



careful experiments on animals has not merely a direct bearing on the point immediately 

 at issue, but ought at the same time to be capable of throwing numerous sidelights on 

 other subjects of physiological and pathological interest. 



In proceeding to give a detailed account of the result of individual experiments, 

 some more or less systematic arrangement of them is essential. The experiments 

 in question, in this instance, might be classified on various principles ; but an arrange- 

 ment having as its basis the fact of the purity or dilution of the medium employed, 

 and sub-divided according to the age of the material, in other words according to the 

 amount of decomposition which it has undergone, appears to be as natural and as 

 convenient as any. Such an arrangement has accordingly been adopted in regard to 

 the experiments of which we now proceed to give an account. 



1. — Experiments on the injection of pure choleraic fluids into the veins of 



ANIMALS. 



(a) The choleraic material used being fresh. 



Experiment I. — A large healthy pariah dog was put under chloroform, and nearly 

 an ounce of choleraic evacuation was injected into the right femoral vein. The 

 material injected consisted, in greater part, of grey watery fluid, but contained in 

 addition numerous minute fragments of the flocculi characteristic of choleraic 

 evacuations. The operation was performed at 8 a.m. 



The animal continued dull and sluggish throughout the course of the day, but 

 did not show the slightest indication of pain. It neither was purged nor vomited, 

 and on the following morning, 24 hours after the operation, it appeared to be 

 much livelier than on the previous evening. The wound in the thigh, however, 

 presented an unhealthy aspect, and there was a considerable amount of swelling 

 around it. The animal became rapidly more depressed and dull during the day, 

 and in the evening appeared to be in a dying condition ; but throughout it showed 

 not a single symptom which could be supposed to resemble those of cholera. 



As it appeared probable that it would die during the night, and that the results 

 of post-^mortem examination would therefore be vitiated, it was anew put under 

 chloroform at 5 p.m., 33 hours after the injection, and the administration continued 

 until respiration ceased. An immediate post-mortem examination was then performed, 

 the results of which were as follows : — 



There was much erysipelatous inflammation of an unhealthy nature around the 

 wound extending for some distance up the flank. On opening the abdomen, the 

 peritoneal cavity was found to contain no fluid, and the peritoneum both in its visceral 

 and parietal layers appeared to be perfectly healthy. The intestines were empty, and 

 in every respect appeared to be perfectly healthy. The liver was extremely fatty, and 

 so soft and friable as to break under the slightest pressure. On its upper surface there 

 was a radiating cicatrix which, from its appearance, seemed to indicate the sit^ of an 



