THE LIVER. 425 



benzoyl-glycogen. On boiling Avith dilute mineral acids it is trans- 

 formed into glucose. Ferments invert it to maltose or glucose, 

 according to the nature of the enzymes at work. 



Isolation and Quantitative Estimation. The perfectly fresh liver, 

 immediately after removal from the animal, is placed in boiling 

 water and divided into small pieces. After boiling for a feAV 

 minutes these are removed, ground to a pulp Avith sand or pulverized 

 glass, and then boiled in a 1 per cent, solution of sodium hydrate, 

 using 400 c.c. for every 100 grammes of tissue. With liver-tissue 

 two to three hours suffice, while Avith muscle-tissue it is best to boil 

 for from four to eight hours. Care must be had during this process 

 that the concentration of the alkali does not exceed 2 per cent. ; to 

 this end Avater is added from time to time. The alkaline extract 

 after filtration is then united with the watery solution first obtained, 

 and neutralized with hydrochloric acid. After concentrating the 

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

 cipitated on cooling by alternate treatment Avith a solution of iodo- 

 mercuric iodide and hydrochloric acid added drop by drop. In 

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

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

 Avith 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 3.6 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, AA r hich are taken 

 from Hammarsten : 



Water. Fat. 



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

 Fatty degeneration 816 " " 87 " " 97 " " 



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



