286 EXCRETION. 



sis, it is impossible to say positively, from these observations 

 alone, that the cjiolesterine is produced in the nervous sys- 

 tem only. But the nutrition of the nerves is undoubtedly 

 most affected ; and these observations, taken in connection 

 with the preceding experiments on animals, point very 

 strongly to such a conclusion. 



Our experiments upon animals were so marked and in- 

 variable in their results, even when performed under differ- 

 ent conditions, that they can leave hardly any doubt of the 

 fact that the blood, in passing through the brain, takes up 

 cholesterine. It is more difficult to show, by actual demon- 

 stration, that the general system of nerves also gives up 

 cholesterine to the blood ; but the fact that the venous blood 

 coming from the extremities contains more cholesterine than 

 the arterial blood, taken in connection with the fact that 

 none of the tissues of the extremities contain cholesterine, 

 except the nerves, renders it more than probable that the 

 nerves, as well as the brain, are the seat of the formation of 

 this principle. 



The observations upon the cases of paralysis are interest- 

 ing, taken in connection with the experiments on animals. 

 Such observations should, of course, be much more elaborate 

 and extended to lead, of themselves, to positive results ; but 

 they go far to confirm our views with regard to the probable 

 origin of cholesterine in the nervous system. 



Elimination of Cholesterine by the Liver. We at- 

 tempted to demonstrate experimentally the separation of 

 cholesterine from the blood by the liver, in the same way 

 that we demonstrated its passage into the blood circulating 

 through the brain. In the first series of experiments on 

 this subject, we endeavored to show, on the same animal, 

 the origin of cholesterine in certain parts, and the mechanism 

 of its elimination. In these experiments, which were only 

 approximative, as we had not then succeeded in extract- 

 ing the cholesterine perfectly pure, we commenced with the 



