337 



Looking upon the effect of the acid injection as due to an action 

 upon the liver, it occurred to me that this organ might be much more 

 directly influenced by injecting the acid into a branch of the portal 

 system instead of the jugular vein. It happens, however, that a cir- 

 cumstance occurs to render this mode of experimenting unsuccessful. 

 Although I have never found the acid lead to a solidification of the 

 blood in the vessels when introduced into the general circulation 

 (indeed, as I have mentioned, the effect is the reverse of this), yet when 

 injected into the portal system it causes the blood belonging to this 

 system to solidify and the vessels to become so plugged up that the 

 circulation of portal blood is completely stopped. I have made five 

 experiments in this way ; and in all but one the effect referred to has 

 occurred. In three of the cases the acid was used undiluted, but in- 

 jected very slowly into one of the mesenteric veins ; and, in each, under 

 an ounce was used : in the fourth, 6 drachms of the acid diluted with 

 12 drachms of water formed the injection employed. All the dogs 

 died in less than one hour and a half, and the trunk of the portal vein 

 with its larger divisions in the liver was found plugged up with solidi- 

 fied blood, so as entirely to check the circulation. The tissue of the 

 liver was in places white and hard, as if it had been chemically acted 

 upon by the acid. There was no sugar to be detected in the urine ; 

 and the liver, submitted to an ordinary examination after death, be- 

 haved in the usual way. From one experiment I learnt that the effect 

 produced by the acid in solidifying the portal blood instantly occurred 

 on the first portion of the injection being made ; so that the portal 

 circulation was at once stopped, which would account for the absence 

 of any sugar in the urine. 



In the experiment where the circulation remained free, | an ounce 

 of the acid was used diluted with 2 ounces of water. The injection 

 was slowly made. The urine in an hour .and a half's time was found 

 to contain a slight amount of sugar. Two hours after the injection, 

 when life was destroyed, the liver was perfectly natural in appearance, 

 and all the vessels were free. There was therefore no engorgement 

 of the spleen nor blackening of the intestine from congestion, as was 

 the case in the other experiments. 



Finding this mode of experimenting proved unavailable, I next 

 tried the effect of introducing the acid into the alimentary canal 

 instead of directly into the portal system. Injecting it into the stomach 



