SACCHARINE COMPOUNDS. 77 



of the liver contains sugar, even in animals that have been fed for some time on 

 animal food alone (a discovery which has been verified in the Giessen Laboratory) 

 that the blood of the hepatic vein of such animals contains sugar, although 

 none is to be found in that of the vena portae and that sugar is contained in 

 the liver of embryos, both of mammals and oviparous animals. In the case of 

 a healthy adult who was guillotined while fasting, it was calculated, from the 

 analysis of a portion of the liver, that the whole mass of it must have contained 

 360 grains of sugar. In Herbivorous animals, whose food contains a large sup- 

 ply of amylaceous and saccharine matter, it appears that the liver does not thus 

 furnish any large quantity of this sugar; whilst on the other hand, a portion of 

 the saccharine constituents of the portal blood seems to be converted into fatty 

 matter in its passage through the liver. But in Carnivorous animals, which 

 have already a supply of fat in their food, but no sugar, the transforming process 

 would seem to be of a different kind, sugar being generated de novo, although 

 from what element of the blood it is produced, has not yet been clearly deter- 

 mined. There seems a strong probability, however, that the production of sugar 

 takes place at the expense of protein-compounds ; and that it is the chief means 

 by which the products of the disintegration of muscular and other albuminous 

 tissues are made available for the maintenance of animal heat by the combustive 

 process ; and this view derives confirmation from the fact, that a new form of 

 Sugar, termed Inosite, whose formula is 120, 16H, 160, has been recently 

 discovered by Scherer in the "juice of flesh," where its presence is almost un- 

 doubtedly to be attributed to the disintegration of muscular tissue. 1 (See also 

 91, VI.) Of the characters of the sugar thus produced in the liver, little is 

 yet definitely known " } but it would appear far to surpass even glucose in the 

 readiness with which it is carried off by the respiratory process ; for, according 

 to the statement of M. Bernard, as much as 12 grammes may be injected into 

 the blood with no more effect upon the urine than is produced by 2.5 grammes 

 of glucose, or by .05 of cane-sugar. 2 



47. This metamorphic action of the liver would seem to be influenced by 

 conditions of the nervous system ; for when the upper part of the medulla ob- 

 longata, near the origin of the pneumogastric nerve, 3 is irritated by puncture or 

 by a slight galvanic shock, the production of sugar in the liver takes place to 

 so great an extent, that a portion of this substance finds its way into the urine, 

 and a temporary artificial diabetes is speedily established. This effect so speedily 

 ensues, that sugar has been detected in the general mass of the blood, and in 

 every secretion formed from it, except the saliva (into which he never found it 

 enter) within twenty minutes after the operation. It is even possible, accord- 



1 "Ann. der Chem. und Pharm.," band Ixxiii. p. 322. 



2 It is considered by M. Bernard, that diabetic sugar rather corresponds to this " sugar 

 of the liver," than it does to glucose. He found no less than 833 grains of sugar in the 

 liver of a diabetic subject ; and he remarks that the liver is generally hypertrophied in 

 this disease. Hence he looks to the liver as its primary seat ; and imputes the glycosuria 

 to an excessive production of sugar in the liver, which would seem then to exercise its 

 metamorphic power upon the azotized constituents of the blood, and thus to destroy the 

 material for the nutritive processes an idea that corresponds well with the phenomena of 

 the disease, which indicate an impoverishment of the nutritive fluid, the solids of the body 

 exhibiting a rapid waste, notwithstanding that there may be an extraordinary appetite, 

 and a very large amount of azotized nutriment may be taken. Moreover, it would seem, 

 from Dr. Prout's observations, as if the presence of a small quantity of saccharine matter 

 in the food tended to promote this metamorphosis in its other constituents ; the eating of 

 a single pear having been observed by him to neutralize all the benefit which had been 

 obtained by an abstinence from saccharine and amylaceous matters, prolonged through 

 several months. 



3 The part of which the injury is most effectual in producing this result, is that which 

 lies in the groove between the corpora restiformia and corpora olivaria, and over the ad- 

 joining part of the latter. 



