296 PATHOLOGICAL EVIDENCE AS TO THE 



cells owing to the wasting of the proteid. The necrotic changes lead 

 to the fatty contents running together into visible droplets. In 

 degenerated nerves the fat droplets are striking objects, but the 

 nerves are poorer, not richer in fat. A patch of yellow softening 

 of the brain in the region of the cuneus yielded 6*17 per cent, fat, 

 while the normal cuneus gave 8-81 per cent. (Rosenfeld). In old 

 pus cells in which microscopically the fat droplets appeared most 

 numerous analysis showed only 1-94 per cent. fat. 



In sections of the normal heart and kidney no histologist sees 

 evidence of fat in the cells, and yet chemical analysis may give 

 15-23 per cent, in the kidney, and as much as 15-16 per cent, in the 

 heart. This shows that microscopical evidences of fatty degenera- 

 tion are utterly untrustworthy. The pre-existent fat may not only 

 come more prominently into view in cells suffering from mal-nutri- 

 tion, but the depot fat may be attracted and lodged within such 

 cells, owing to the effort of the dying protoplasm to maintain its 

 energy. 



Thus phosphorus poisoning has been quoted over and over again 

 as a typical example of fatty degeneration of proteid, but Rosenfeld 

 has collected much evidence to show that the fattiness is brought 

 about by the transference of depot fat to the poisoned organs. 

 He robbed dogs to the utmost of their depot fat by fasting, next 

 filled up the depots with mutton fat by feeding, then freed the 

 liver from fat by a second and shorter period of fasting, and 

 finally gave phosphorus. The liver of the control dogs yielded 

 7 - 9 per cent, of the dry substance as fat with the normal iodine 

 number for dog's fat (100-99), while the poisoned dog's liver 

 yielded 41* 44 per cent, fat, with the iodine number of mutton fat 

 (57'4). The mutton fat had been transported from the depots to 

 the liver. 



When Rosenfeld had fasted animals to such an extent that 

 the depot fat had disappeared to the utmost extent, he found 

 phosphorus produced no increase of fat in the liver. Thus 



