466 SECRETION. 



experiment of Bernard, showing that sugar is formed in a liver removed from the body 

 and washed sugar-free by a stream of water passed through its vessels, demonstrated the 

 possibility of the production of sugar post mortem, so strongly claimed by Pavy as the 

 .only condition under which it is ever formed ; still, it does not seem possible to deny the 

 sugar-producing function of the liver, in view of the conclusive experimental proof of the 

 constant presence of glucose in the bloocj. of the hepatic veins. 



From our own experiments, we have come to the conclusion that Dr. Pavy and those 

 who adopt his views cannot consistently deny that sugar is constantly formed in the liver 

 and discharged into the blood of the hepatic veins; nor can Bernard and his followers 

 ignore the fact that the liver does not contain sugar during life ; although, as has been 

 shown by Pavy, and more specifically by M'Donnell, sugar appears in the liver in great 

 abundance soon after death. 



In the experiments that we have just detailed, which are simply typical examples of 

 numerous unrecorded observations, we attempted to verify the observations of Pavy 

 without losing sight of the facts observed by Bernard, and to verify the experiments of 

 Bernard in the face of the apparently contradictory statements of Pavy. "When an ani- 

 mal is in perfect health, has been kept quiet before the experiment, and a piece of the 

 liver is taken from him by two sweeps of the knife, the blood rinsed from it and the tis- 

 sue cut up into water already boiling, the whole operation occupying only ten seconds 

 (as was the case in Experiment III.), the liver is as nearly as possible in the condition in 

 which it exists in the living organism. As this was done repeatedly in animals during 

 digestion and in the intervals of digestion, and an extract was thoroughly made without 

 finding any sugar, we regarded the experiments of Pavy as entirely confirmed and the fact 

 demonstrated that the liver does not contain sugar during life. On the other hand, when 

 we made the experiment upon the liver as above described, and, in addition, took specimens 

 of the portal blood and the blood from the hepatic veins, under strictly physiological 

 conditions (as was done in Experiment IV.), and found no sugar in the portal blood or 

 in the substance of the liver, but an abundance in the blood of the hepatic veins, it was 

 impossible to avoid the conclusion that the sugar was formed in the liver and was washed 

 out in the blood as it passed through. 



In treating of the mechanism of the formation of sugar in the liver, we shall describe 

 more fully the glycogenic matter ; but, taking into consideration the demonstration of 

 the presence of sugar in the blood of the hepatic veins by Bernard ; his discovery of the 

 post-mortem production of sugar in a liver washed sugar-free, probably from a substance 

 remaining in the liver and capable of being transformed into sugar ; the negative results 

 of the examinations of the liver for sugar by Pavy ; and, adding to this our own experi- 

 ments upon all of these points, we are justified in adopting the following conclusions : 



1. A substance exists in the healthy liver, which is capable of being converted into 

 sugar ; and, inasmuch as this is formed into sugar during life, the sugar being washed 

 away by the blood passing through the liver, it is perfectly proper to call it glycogenic, 

 or sugar-forming matter. 



2. The liver has a glycogenic function, which consists in the constant formation of 

 sugar out of the glycogenic matter, this being carried away by the blood of the hepatic 

 veins, which always contains sugar in a certain proportion. This production of sugar 

 takes place in the carnivora, as well as in those animals that take sugar and starch as 

 food ; and it is, essentially, independent of the kind of food taken. 



3. During life, the liver contains the glycogenic matter only and no sugar, because 

 the great mass of blood which is constantly passing through this organ washes out the 

 sugar as fast as it is formed ; but, after death or when the circulation is interfered with, 

 the transformation of glycogenic matter into sugar goes on ; the sugar is not removed 

 under these conditions, and can then be detected in the substance of the liver. 



Characters of the Liner- Sugar. Very little is to be said regarding the chemical pe- 



