FATTY ELEMENTS OF FOOD, AND ON. FATTENING. 427 



virtue of this power that the enigma is to be explained, of the source 

 whence the myriads that people the deep derive their food. 



But is it absolutely true that herbivorous animals only abound in 

 fat? Who has not seen fat dogs and cats; and in the Cordilleras, 

 where palm-trees abound, there is a particular species of bear, which 

 lives in a great measure on the oily palm-nuts and young shoots of 

 the palm-tree, which becomes remarkably fat, and proves a great 

 attraction to the tigers of the country.* 



Before coming to a close with this discussion, I think it right to 

 refer to the experiments of M. Magendie, who has so well establish- 

 ed the fact, that the chyle of animals fed on fat food contains a large 

 quantity of fat ; and that animals kept long on such food frequently 

 become affected with what is called the fatty liver. f 



To sum up, then, experiment 'demonstrates that hay contains a 

 larger quantity of fatty matter than the milk and excretions which it 

 forms ; and that it is the same with all the other mixtures and varie- 

 ties of food that are usually given to animals. 



That oil-cake increases the production of butter, and that, like 

 maize, it owes the fattening properties it possesses to the large 

 quantity of oil it contains. 



That there is the most perfect analogy between the production 

 of milk and the fattening of animals ; that potatoes, beet, carrot, and 

 turnip, only fatten when they are conjoined with substances that 

 contain fatty matters, such as straw, corn, bran, and oil-cake of 

 various kinds. 



That in equal weights, gluten mixed with starch, and flesh meat 

 abounding in fat, have a fattening influence on the hog, which differs 

 in the relation of 1 to 2. 



Lastly, that fat food — food which will afford fat in the digestive 

 canal — appears to be the indispensable condition of fattening. If it 

 be necessary that the respiration be diminished or lessened in extent, 

 this is only that the fatty substances taken into the stomach, and 

 which have made their way into the blood, may not be oxidated, 

 may not be burned ; not that their formation may be favored. 



All these facts are in such perfect harmony with the simple view 

 of assumption and assimilation of fatty matters, that it is difficult to 

 conceive on what foundation the opinion can repose which would 

 have them composed out of their elements in the animal body. 

 Nevertheless, 1 am myself the first to admit, that more extensive 

 experience may l^ad to the modification or even entire change of 

 the opinion which I advocate. The facts on which that opinion is 

 based, despite their number, are not probably yet sufficient to }on- 

 stitute a perfectly satisfactory or conclusive theory. New researches 



* These bears, evidently, cease to be cnrnivorous while they live on pilm-nuts and 

 leaves. For niv own part, I do not think the point seUled yet. The fatty inntter of 

 the j^jenerality of vegetables is wax rather than grease. And then some of the herbiv- 

 orous tribes seem never to get fat. — Eng. Ed. 



t I may here state the contrary- fact, as announced to me by a physiological friend, 

 In whose report I place great reliance, that the chyle of animals fed with substances 

 that give mere traces of waxy matter, contains fat or oil that can be collected in larg* 

 drtpi — Ewa Ed. 



