METABOLISM 175 



could, with only one or two exceptions, be accounted for by the 

 fat and protein of the feed. They, therefore, characterized the 

 formation of fats from carbohydrates as improbable. The some- 

 what general impression that Voit absolutely denied the pro- 

 duction of fat from carbohydrates is incorrect, although he re- 

 garded it as improbable and unproved. Indeed, he came later to 

 admit the truth of the opposite view and even furnished from 

 his own laboratory experimental evidence in its support. Never- 

 theless, his earlier opinion as to its improbability obtained wide 

 currency and in the hands of his followers became almost a 

 dogma, so that protein was given a vital and preponderant im- 

 portance the effect of which has been unfortunate both for the 

 development of the science of nutrition in general and upon the 

 theory of stock feeding in particular. 



Henneberg's estimate of the maximum fat production from 

 protein was soon virtually accepted as an established fact and 

 with the use of this high figure it was easy to compute from most 

 of the experiments on fat production then on record that the fat 

 and protein of the feed were sufficient to account for the fat 

 produced. Similar computations upon a large number of later 

 feeding experiments l yielded similar results, so that belief in 

 the non-formation of fat from carbohydrates was further 

 strengthened. 



One notable exception to the rule, however, were the experi- 

 ments made by Lawes and Gilbert in 1850 upon the fattening of 

 swine. These were comparative slaughter tests (284) in which 

 the gain of fat was determined by comparing the weight and 

 composition of similar animals, one before and the other after 

 fattening. They were, accordingly, subject to a somewhat 

 considerable range of error, but even on the most extreme as- 

 sumptions it was impossible in^six out of the nine experiments 

 to account for the fat actually produced by the supply of fat 

 and protein in the feed. These investigators, therefore, con- 

 tinued to maintain, in spite of much adverse criticism, the 

 formation of fat from carbohydrates, although their experi- 

 ments hardly secured the recognition which they deserved. 



As time went on, however, results began to accumulate which, 

 like Lawes and Gilbert's showed a much larger production of 

 fat than could possibly be ascribed to the fat and protein of 



See the author's Manual of Cattle Feeding, p. 177. 



