Formation of Fat in the Animal Body. 21 



in this note M. Dumas says, — " M. Liebig is of opinion that 

 graminivorous animals produce fat out of sugar and starch, 

 while MM. Dumas and Boussingault consider it as a fixed rule, 

 that animals, of whatever kind, produce neither fat nor any 

 other alimentary substance ; that they receive from the ve- 

 getable kingdom all their aliments, whether it be sugar, starch, 

 or fat. 



" Were the proposition of M. Liebig founded upon fact, 

 the general formula of chemical equivalents of both kingdoms, 

 as defined by MM. Dumas and Boussingault, would be false. 

 But the commission on gelatine has dispelled all doubt, that 

 the animals which eat fat are the only ones in which fat is 

 found to accumulate in the tissues." 



The origin of fatty compounds in animal bodies has, through 

 this note, become a question of dispute. 



As far as regards myself, I have neither time nor inclina- 

 tion to engage in it ; the object of my observations was to 

 leave no doubt of the physiological importance of the fat of 

 animal bodies, as regards the process of respiration. In this 

 view MM. Dumas and Boussingault agree with me. 



I think it now right to explain the reasons which induced 

 me to consider that little or no increase of fat in animal bodies 

 was to be ascribed to the ingredients of the food containing fat, 

 consumed by graminivorous animals. 



The food which, according to the experience of physicians, 

 has a decided influence on the formation of fat in animal bodies, 

 is that which is richest in starch, sugar, and other substances 

 of a similar constitution. 



Rice, Indian corn, beans, peas, linseed, potatoes, beet are 

 used in husbandry in large quantity with great effect for fat- 

 tening, that is, for the increase of flesh and fat. In Bavaria 

 beer is used as a stimulating food for the increase of fat. 



Whether much or little importance may be ascribed to the 

 universal experience of husbandry, it is certain that animals 

 which are fed upon these different substances, under certain 

 conditions (abundance of food, little exercise, high tempera- 

 ture, &c), after some time become much fatter than before. 

 This fat proceeds from the food. Rice, beans and peas have 

 been carefully analysed by various chemists. Braconnot 

 found in Carolina rice 0*13 per cent, of oil, in Piedmont rice 

 0*25 per cent.; Vogel found in rice 1*05 per cent. 



According to these analyses, the organism received from 

 1000 lbs. of Carolina rice 1*3 lb. or 2*5 lbs., or according to 

 Vogel lO^lbs. of fat. 



Peas contain, according to Braconnot, 1*20 of a substance 

 soluble in aether, which he calls leafgreen (chlorophyll). The 



