THE FORMATION OF FAT IN THE ANIMAL BODY. 191 



to Playfair and Boeckniann, the ratio of nitrogen to carbon is 1:3.451, 

 according to Yoit it is 1:3.GS4, a ratio 6.7 jier cent greater than 

 that of Playfair and Boeckniann. According to Rubner, the ratio of 

 nitrogen to carbon is 1:3.277, and according to Pfliiger, who takes into 

 account the glycogen in the meat, it is 1 : 3.22. The difference between 

 Pfliiger's and Voit's ratios is sufficient to account for all the fat which 

 Voit assumed was formed from protein. Pfliiger shows this very plainly 

 in most of A'oit's experiments. The classic experiments of Pettenkofer 

 and Yoit offer no proof of the formation of fat from protein. 



The other proofs of the formation of fat from protein were either 

 overthrown by Pfliiger or shown to point just as clearly to the forma- 

 tion of fat from carbohydrates as from jirotein. 



Lack of space forbids the consideration of this point in detail, which 

 has been given more fully elsewhere.' 



The conclusion of Salkowsky and Munk that Pfliiger's criticism of 

 Voit is in the main justifiable seems warranted, and it may be said 

 that Pfliiger's recalculation of the results has overthrown Yoit's funda- 

 mental proposition. By his new law of nutrition Pfliiger makes the 

 carbohydrates and fat of the food consumed the sole sources of fat. 



Among the more recent investigations which have been reported 

 that of a Japanese, Kumagawa,^ should be mentioned. In his careful 

 resume, "The formation of fat," he makes the following points: (1) 

 The animal body (dog) under normal conditions has no tendency to 

 produce fat from protein. (2) If protein is supplied in so large a quan- 

 tity that it exceeds all the needs of the organism the nitrogen-free 

 nutrients supplied with the protein are no longer utilized in the organ- 

 ism, but the fat is stored up and the carbohydrates supplied are trans- 

 formed into fat and also stored. 



Both Pfliiger and Kumagawa deny the possibility of the formation 

 of fat from protein which has been so long assumed. Both consider 

 that the fat and carbohydrates of the food are the only sources from 

 which fat can be formed in the organism. 



To the practical stock raiser a knowledge .of the scientific aspect of 

 the subject is of great value. It is of the utmost imjiortance for him 

 to realize in fattening animals that in addition to a definite quantity of 

 protein, which is absolutely essential, those feeding stuffs must be used 

 which contain an abundance of fat and carbohydrates. 



iSoskin, Jour. Landw,, 42 (1894). 



«Mitt. med. Fac. k. jap. Univ. Tokio, 3 (1894), No. 1. 



