FORMATION OF SUGAR IN THE LIVER. 201 



urine has often appeared to be altogether out of proportion to that 

 which could be accounted for by the vegetable substances taken as 

 food. The experiments of Bernard, the most important of which 

 we have repeatedly confirmed, in common with other investigators, 

 show that in these instances most of the sugar has an internal 

 origin, and that it first makes its appearance in the tissue of the 

 liver. 



If a carnivorous animal, as, for example, a dog or a cat, be fed 

 for several days exclusively upon meat, and then killed, the liver 

 alone of all the internal organs is found to contain sugar among its 

 other ingredients. For this purpose, a portion of the organ should 

 be cut into small pieces, reduced to a pulp by grinding in a mortar 

 with a little water, and the mixture coagulated by boiling with an 

 excess of sulphate of soda, in order to precipitate the albuminous 

 and coloring matters. The filtered fluid will then reduce the oxide 

 of copper, with great readiness, on the application of Trommer's 

 test. A decoction of the same tissue, mixed with a little yeast, will 

 also give rise to fermentation, producing alcohol and carbonic acid, 

 as is usual with saccharine solutions. On the contrary, the tissues 

 of the spleen, the kidneys, the lungs, the muscles, &c., treated in 

 the same way, give no indication of sugar, and do not reduce the 

 salts of copper. Every other organ in the body may be entirely 

 destitute of sugar, but the liver always contains it in considerable 

 quantity, provided the animal be healthy. Even the blood of the 

 portal vein, examined by a similar process, contains no saccharine 

 element, and yet the tissue of the organ supplied by it shows an 

 abundance of saccharine ingredients. 



It is remarkable for how long a time the liver will continue to 

 exhibit the presence of sugar, after all external supplies of this 

 substance have been cut off. Bernard kept two dogs under his own 

 observation, one for a period of three, the other of eight months, 1 

 during which period they were confined strictly to ji diet of animal 

 food (boiled calves' heads and tripe), and then killed. Upon exa- 

 mination, the liver was found, in each instance, to contain a propor- 

 tion of sugar fully equal to that present in the organ under ordinary 

 circumstances. 



The sugar, therefore, which is found in the liver after death, is a 

 normal ingredient of the hepatic tissue. It is not formed in other 

 parts of the body, nor absorbed from the intestinal canal, but takes 



1 Nouvelle Fonction du Foie, p. 50. 



