108 DIGESTION. LECT. V. 



gestion of fatty matters, wlfich are taken in very large 

 quantities into the stomachs of the carnivora, and which, 

 undergoing scarcely any modifications in their composition, 

 are conveyed into the adipose tissues. 



For this purpose, I must say a few words on the impor- 

 tant question lately mooted by chemists, respecting the ori- 

 gin of fat in herbivorous animals. 



Liebig maintains, that it is produced by means of a 

 transformation of fecula. This looses a portion of its oxy- 

 gen, which is expelled from the organism in combination 

 with carbon. 



Dumas, Boussingault, and Payen, on the contrary, be- 

 lieve that the quantity of fatty matter in hay, beet-root, and 

 straw, is sufficient to account for the amount of fat found 

 in animals fed with these substances. Boussingault has de- 

 monstrated the truth of this opinion by observations made 

 on a cow. He found, that whilst the quantity of fatty mat- 

 ter existing in the aliments on which she was nourished 

 weighed 1614 grammes, the amount found in her milk was 

 only 1413 grammes; showing an excess of 201 grammes 

 of the fat contained in the aliments, over that obtained from 

 the products of the animal. 



The same chemist also found, by means of experiments 

 made on pigs and geese, that in these animals a much larger 

 quantity of fat is produced than is contained in their food : 

 and Persoz has arrived at the same conclusion. 



It cannot, therefore, be denied that the animal economy 

 possesses the faculty of transforming a portion of substances 

 used for nourishment into fat. Chemical knowledge is of" 

 no assistance to us, in this instance, in explaining this trans- 

 formation.* 



* Chemists have succeeded in converting sugar into fatty matter. 

 " When a solution of sugar is left to ferment, at a high temperature, in 



