Intelligence and Miscellaneous Articles.^ 329 



tains no sugar, and that the blood which leaves the organ by the 

 hepatic veins is always charged with it, we must admit that the 

 blood acquires the saccharine principle in passing through the hepatic 

 texture, or in other words, that the liver is endowed with a peculiar 

 function in virtue of which sugar is produced. 



The liver, therefore, performs two functions at the same time, 

 namely, the secretion of bile and the production of sugar ; and the 

 latter function commences even before birth, for I have detected 

 sugar in the liver of the young of mammalia and birds at different 

 periods of foetal life. It is remarkable, that while the bile, like other 

 intestinal secretions, is j)oured out into the alimentary canal, the 

 sugar, on the contrary, mixed with the portal blood returned from 

 the intestines and spleen, is carried out into the general circulation, 

 and disappears in contributing to the phsenomena of nutrition. This 

 separation of the bile and sugar, however, occurs only in vertebrata, 

 for in mollusca I have found the biliary fluid highly charged with 

 saccharine matter. 



The sugar produced in the liver presents the chemical characters 

 of glucose. Along with M. Barreswil, I have ascertained the fol- 

 lowing properties : — 



1. The saccharine principle of the liver ferments when put in con- 

 tact with yeast, and yields alcohol and carbonic acid. 



2. Its solution is rendered brown by the caustic alkalies, and re- 

 duces the tartrate of copper dissolved in potash*. 



I ought to add, that the hepatic sugar undergoes spontaneous 

 destruction in contact with blood and animal textures much more 

 rapidly than ordinary glucose ; a circumstance indicating that, to 

 operate in favourable conditions, the search for sugar in the liver 

 should be made on animals recently dead.- ^^ b-jJoa:^ 



3. Influence of the nervous system on the formation- o#-W^¥ ill 

 the liver. 'ii ^Kis si 



The formation of sugar in the liver is a function j^lahed under the 

 immediate influence of the nervous system. 



In vertebrata, the liver receives two kinds of nerves supplied from 

 the pneumogastric and the solar plexus. In this, as in other func- 

 tions, it is difficult to determine the kind of participation which the 

 nervous system has in the chemical acts of nutrition. It is, how- 

 ever, incontestable that some of the pheenomena of nutrition cannot 

 be produced external to the living individual, and are connected in 

 an immediate manner with the integrity of the nervous system ; so 

 that we can extinguish, exalt, or disturb these chemical phsenomena 

 simply by modifying the nervous organs which influence them. In 

 particular, those functions, generally periodical, designated in phy- 

 siology as secretions, are so placed ; and I shall show that the pro- 

 duction of sugar in the liver belongs to the same category. 



Thus, for example, whatever be the kind of food, \Ve can cause 

 the complete disappearance, in a few hours, of the saccharine matter 

 of the liver in dogs or rabbits by the section of the pneumogastric 

 nerves in the middle region of the neck. The same result occurs 



* The latter test is the one commonly used by M. Bernard to detect the 

 presence of sugar. * _ . ..... -^ 



