PRODUCTION OF SUGAR IN THE LIVER. 309 



tion, avoiding the administration of an anaesthetic, and 

 taking the blood so rapidly that no sugar could be formed 

 by the liver post mortem. These experiments leave no doubt 

 of the fact that, during life and in health, the blood, as it 

 passes through the liver and is discharged by the hepatic veins 

 into the vena cava, contains sugar, which is formed by the 

 liver, independently of the sugar and starch taken as food. 



Does the Liver contain Sugar normally during Life f 

 This is the only question upon which the results of reliable 

 experiments have been entirely opposite. Bernard made the 

 greater part of his observations by analyzing the substance of 

 the liver ; and he arrived at most of his conclusions with re- 

 gard to the variations in the glycogeuic function, from esti- 

 mates of the proportion of sugar in the liver under different 

 conditions. For many years we have been in the habit of re- 

 peating these experiments, with like results, and never failed 

 to find sugar, under normal conditions of the system. "We 

 were formerly in the habit of making the demonstrations of 

 the formation of sugar in the liver upon animals that had 

 been etherized ; and then we always obtained a brilliant pre- 

 cipitate from the clear extract of the substance of the liver 

 boiled with the test-liquid. The experiment was performed 

 in this way before we had acquired sufficient dexterity to 

 seize the portal vein readily and to go through with the 

 necessary manipulations with rapidity. "We subsequently 

 made the operation by first suddenly breaking up the me- 

 dulla oblongata, then making a small incision into the 

 abdominal cavity, seizing the portal vein instantly, and 

 following out the remaining steps of the experiment without 

 delay. In this way, although sugar was always found in the 

 blood of the hepatic veins, we frequently failed to obtain a 

 distinct reaction in the extract of the liver ; and it seemed, 

 indeed, that the more accurately and rapidly the operation 

 was performed, the more difficult was it to detect sugar in 

 the hepatic substance. 



