440 Mr. J. B. Lawes and Dr. Gilbert on the Sources 



tributed to the formation of fat. That animals nevertheless do 

 not become fat when fed upon very highly nitrogenous food, 

 Voit considers sufficiently explained by the greater number of 

 blood-corpuscles, the result of such diet, and the greatly increased 

 activity of oxidation of nitrogenous substance under such con- 

 ditions ; whilst, on the other hand, the accumulation of fat when 

 fat and carbo-hydrates are supplemented to a liberal nitrogenous 

 diet he considers to be connected with the much less active 

 oxidation of the nitrogenous substance and fatty matter that then 

 takes place, rather than attributable to the direct production of 

 fat from the carbo-hydrates. 



In the discussion which followed the reading of Professor 

 Voit's paper, Baron Liebig forcibly called in question Professor 

 Voit's conclusions, maintaining not only that it was inadmis- 

 sible to form conclusions on such a point in regard to Herbivora 

 from the results of experiments made with Carnivora, but also 

 that direct quantitative results obtained with herbivorous animals 

 had afforded apparently conclusive evidence in favour of the 

 opposite view. 



Since the Munich Meeting, Hermann von Liebig, son of 

 Baron Liebig, has written a paper on the subject*, in which, 

 admitting the probability that fat may be formed from nitro- 

 genous substance, he nevertheless concludes that this is neither 

 its only, nor even its chief source, in the ordinary feeding of 

 Herbivora. 



After referring to the leanness of the South Russian shepherds, 

 who consume very large quantities of dried meat, and to the 

 rotundity of the peasantry, especially the women, in districts 

 where bread and fruits constitute the chief articles of food, H. 

 von Liebig proceeds to illustrate the formation of fat from non- 

 nitrogenous constituents of food by our domestic Herbivora, by 

 the calculation of the results of numerous experiments made 

 with cows in 1857, by Knop, Arendt, and Behr, in which the 

 details as to food, live-weight, and quantity and composition of 

 milk, were accurately recorded. According to the mode of cal- 

 culation adopted, it appeared that, after deducting from the 

 amount of nitrogenous substance taken in the food that estimated 

 to be required by the system for other purposes, there was 

 generally little or none remaining for the production of fat. In 

 his calculations, however, H. von Liebig, besides taking into 

 account the probable amount of nitrogenous substance stored up 

 in increase with gain of weight, or set at liberty when there was 

 loss of weight, as the case might be, deducted from the amount 

 of nitrogenous substance given in the food, not only that re- 

 quired for the production of the caseine of the milk, but also 

 * Versuchs-Stationen Organ, vol, viii. No, 3, 1866, 



