404 THE GLANDULAR ORGANS. 



and neutralized with hydrochloric acid. After concentrating the 

 resulting solution, the remaining albumins, notably gelatin, are pre- 

 cipitated on cooling by alternate treatment with a solution of iudo- 

 mercuric iodide and hydrochloric acid added drop by drop. In 

 the filtrate the glycogen is precipitated with an excess of alcohol. 

 It is collected on a filter, washed with 60 per cent, alcohol, then 

 with absolute alcohol and ether, and is finally dried in a desic- 

 cator over sulphuric acid. From the weight thus obtained, that of 

 the combined mineral salts must be deducted after incineration. 



Glucose. The amount of glucose in the perfectly fresh liver 

 varies between 0.2 and 0.6 per cent., but rapidly increases at the 

 expense of the glycogen after the removal of the organ from the 

 body. To obtain results which represent the actual amount that 

 is present during life, it is hence necessary to eliminate the inverting 

 action of the living protoplasm and of ferments by placing the organ 

 in boiling water immediately after the death of the animal. It is 

 then finely minced, thoroughly extracted with boiling water, and the 

 sugar determined in the filtrate according to the usual methods. 



Fat. The amount of fat which is found in the liver is quite 

 large, as compared with the other organs of the body, and normally 

 varies between 2 and 3.5 per cent. It is deposited in the cells, and 

 beginning along the periphery of the acini increases in amount toward 

 the centre. It is most abundant after meals, and to a certain degree is 

 dependent upon the amount of fat ingested. Under suitable condi- 

 tions the infiltration may become so marked as to simulate fatty 

 degeneration ; but, in contradistinction to fatty infiltration, we find 

 that in fatty degeneration the amount of the solids is markedly 

 diminished. The amount of water in fatty infiltration is diminished, 

 while in degenerative changes it is perhaps slightly increased. These 

 relations are exemplified by the following figures, which are taken 

 from Hammarsten : 



Water. Fat. 



Normal liver . . . 770 pro mille 20-35 pro mille 207-195 pro mi lie. 



Fatty degeneration 816 " " 87 " " 97 



Fatty infiltration . 616-621 " " 195-240 " " 184-145 " " 



Extractives. The extractives which are found in the liver, 

 aside from glycogen and glucose, are notably xanthin-bases, which 

 are derived from the nuclei. They comprise xanthin, hypoxanthin, 

 guanin, and adenin. Conjointly they represent about 4.52 pro mille 

 of the dried tissue. They can be isolated, according to the method 

 described on page 363. In addition we find small amounts of urea, 

 uric acid, paralactic acid, and jecorin. Cystin also has been isolated 

 from the normal liver of a horse and from that of the porpoise, but 

 it is questionable whether the substance can actually be regarded as 

 a normal constituent of the gland. It has once been obtained from 

 the liver of a patient who during life had eliminated cystin in the 

 urine. Under pathological conditions, and especially in acute yellow 



