264 CHEMICAL COMPOSITION OF THE LIVER-CELLS. 



During life, under normal conditions, the glycogen in the liver is either not 

 transformed into grape-sugar (Pavy), or, what is more probable, only a very small 

 amount of it is so changed. The normal amount of sugar in blood is 0*5 to 1 per 

 1000, although the blood of the hepatic vein contains somewhat more. A consider- 

 able amount is transformed into sugar only when there is a decided derangement of 

 the hepatic circulation, and in these circumstances the blood of the hepatic vein 

 contains more sugar. The glycogen undergoes this change very rapidly after death, 

 so that a liver which has been dead for some time always contains more sugar and 

 less glycogen. 



The diastatic ferment in the liver is small in amount, and can be obtained from 

 the extract of the liver-cells by the same means as are applicable for obtaining 

 other similar ferments, such as ptyalin ; but it does not seem to be formed within 

 the liver-cells, but only passes very rapidly from the blood into them. The ferment 

 seems to be rapidly formed when the blood-stream undergoes considerable derange- 

 ment. A similar ferment is formed when red blood-corpuscles are dissolved (Tiegel), 

 and, as red blood-corpuscles are continually destroyed within the liver, there is one 

 source from which the ferment may be formed, whereby minute quantities of sugar 

 would be continually formed in the liver. 



According to Seegen, the blood of the hepatic vein contains twice as much sugar (0 '23 per 

 cent.) as that in the portal vein (0*119 percent.); observations on dogs showed that the blood 

 flowing through the liver gives up over 400 grins, sugar in 24 hrs. Hence, in camivora, the 

 greatest part of the C of the animal food must pass into sugar, so that the formation of sugar 

 in the liver, and its decomposition in the blood, or in the organs traversed by the blood, must 

 be a very important function of the metabolism. Seegen is also of opinion that the liver- 

 glycogen takes no part in the formation of sugar in the liver. 



[Blood when perfused through a freshly excised liver, (or through the kidneys, lungs, or 

 muscles), gains lactic acid (G. Aglioand JVissokowitsch).~\ 



(3) Fats, in the form of highly refractive granules, occur in the liver-cells, as 

 w r ell as free in the bile-ducts ; sometimes, when the food contains much fat (more 

 abundant in drunkards and the phthisical), olein, palmatin, stearin, volatile fatty 

 acids, and sarcolactic acid are found. 



There are also found traces of cholesterin, minute quantities of urea, uric acid, and the little- 

 known body jecorin. [Jecorin, discovered by Drechsel, contains S and P, and reduces alkaline 

 solutions of copper like grape-sugar. It is also found in the spleen, muscles, and blood 

 (Baldi). The liver of birds contains a relatively large amount of uric acid, even 6 to 14 times 

 as much as the bood (v. Schrceder).] [Leucin (?guanin), sarkin, xanthin, cystin, and tyrosin 

 occur pathologically in certain diseases where marked chemical decompositions occur.] 



[Fatty Dengeneration and Infiltration. Fatty granules are of common occurrence within 

 the cells of the liver, constituting fatty infiltration, and when not too numerous do not seem 

 to interfere greatly with the functions of the liver-cells. Fatty particles occur if too much 

 fatty food be taken, and they are commonly found in the livers of stall-fed animals; the 

 well-known pdte-dc-foic gras is largely composed of the livers of geese, which have been fed 

 on large amounts of farinaceous food, and which have been subjected to other unfavourable 

 hygienic conditions. Fatty granules are recognised by their highly refractive appearance, by 

 their solubility in ether, and by being blackened by osmic acid.] 



(4) The inorganic substances in the human liver are potassium, sodium, 

 calcium, magnesium, iron, manganese, chlorine, and phosphoric, sulphuric, car- 

 bonic, and silicic acids ; while copper, zinc, lead, mercury, and arsenic may be 

 accidentally deposited in the hepatic tissue. 



[Tizzoni's Reaction. If a section of a liver (especially of a young animal) hardened in alcohol 

 be treated with a solution of potassic ferrocyanide, and then with dilute hydrochloric acid, as a 

 general rule the preparation becomes blue, even to the naked eye ; but failing that, one cau 

 usually see with the microscope granules of Prussian blue in the protoplasm of the cells, indi- 

 cating the presence of free iron oxide. ] 



175. DIABETES MELLITTJS AND GLYCOSURIA. [Glycosuria is char" 

 acterised by the presence of grape-sugar in the urine. According to Brucke a 

 trace of sugar exists normally in urine, and when this amount is increased we 

 have glycosuria. When the normal amount of grape-sugar in the blood is 



