EXCRETORY FUNCTION OF THE LIVER. 



tity of cholesterine absorbed by the blood in its passage 

 through the brain. In the first instance the increase was 

 but 3-4:88 per cent., while in the latter it was 23'307 per cent. 



The natural conclusions to be drawn from these observa- 

 tions, with regard to the origin of cholesterine in the econ- 

 omy, are the following: It has been ascertained that the 

 brain and nerves contain a large quantity of this substance, 

 which is found in hardly any other of the tissues of the body ; 

 and these experiments, especially Experiments III. and IV., 

 show that the blood that comes from the brain contains a 

 much larger quantity of cholesterine than the blood supplied 

 to this organ. 



The conclusion is, then, that cholesterine is produced in 

 the brain, and is taken up by the blood as it passes through 

 this organ. 



But the brain is not the only part where cholesterine is 

 produced. It will be seen by Experiment II. that there is 

 4'134 per cent., and in Experiment III. 6'30S per cent, of 

 increase in the cholesterine in the passage of the blood 

 through the inferior extremities, and probably about the 

 same in other parts of the muscular system. In examining 

 these tissues chemically, we find that the muscles contain no 

 cholesterine, but that it is abundant in the nerves ; and as 

 we have found that the proportion of cholesterine is im- 

 mensely increased in the passage of the blood through the 

 great centre of the nervous system, taken, as the specimens 

 were, from the internal jugular, which collects the blood 

 mainly from the brain and very little from the muscular sys- 

 tem, it is rendered very probable that, in the general venous 

 system, the cholesterine which the blood contains is produced 

 in the substance of the nerves. 



If this be true, and if cholesterine be one of the prod- 

 ucts of the disassimilation of nervous tissue, its formation 

 would be proportionate in activity to the nutrition of the 

 nerves ; and any thing which interfered to any great extent 

 with their nutrition would diminish the quantity of choleste- 



