FOOD. 121 



fed with honey, which contains some waxy and other matters beside 

 Bii.srar, they thrive upon it ; and produce, in a given time, a larger quantity 

 of fat than was contained in the food. 



The same thing was established by Boussingault with regard to 

 starchy matters. He found that in fattening pigs, though the quantity 

 of fat accumulated by the animal considerably exceeded that contained 

 in the food, yet fat must enter to some extent into its composition to 

 maintain the animal in good condition ; for pigs, fed on boiled potatoes 

 alone (an article abounding in starch but nearly destitute of oily matter), 

 fattened slowly and with difficulty ; while those fed on potatoes mixed 

 with a greasy fluid fattened readily, and accumulated much more fat 

 than was contained in the food. In order, therefore, that an animal 

 become fattened, it must be supplied not only with the materials of the 

 fat itself, but with everything else necessary to maintain the body in a 

 healthy condition. Oleaginous matter, is one of these substances. 

 We cannot assume that the fats taken in with the food are simply 

 absorbed, and deposited unchanged in the system. They may be in 

 great measure decomposed or transformed in the process of nutrition ; 

 those which appear as constituents of the tissues being products of 

 new formation, derived perhaps from a variety of sources. 



It is certain that either one or the other of these two groups of 

 substances, saccharine or oleaginous, must enter into the composition 

 of the food ; and furthermore, that, though oily matter may sometimes 

 be produced in the body from the sugars, it is also necessary that it be 

 supplied under its own form. In the food of man they are naturally 

 associated in many vegetable alimentary matters ; while the fats are 

 supplied in addition from a variety of animal substances. 



But neither the carbohydrates nor the fats, alone or associated with 

 each other, are sufficient for nutrition. Magendie found that dogs, fed 

 exclusively on starch or sugar, perished after a short time with symp- 

 toms of profound disturbance of the nutritive functions. An exclusive 

 diet of butter or lard had a similar effect. The animal became exceed- 

 ingly debilitated, though without much emaciation ; and after death the 

 internal organs and tissues were found infiltrated with oil. Boussin- 

 gault* performed a similar experiment, with like result, upon a duck, 

 which was kept on an exclusive regimen of 90 to 100 grammes of 

 butter per day. At the end of three weeks it died of inanition, although 

 every part of the body was saturated with oily matter. 



Lehmann was led to the same result by experiments upon him- 

 self, while investigating the effect produced on the urine by different 

 kinds of food.f He confined himself first to a purely animal diet for 

 three weeks, afterward to a purely vegetable diet for sixteen days, 

 without marked inconvenience. He then put himself upon a regimen 

 of non-nitrogenous substances, starch, sugar, gum, and oil, but was only 



* Chimie Agricole. Paris, 1854, p. 166. 



f Journal fur praktische Chernie, Band xivii., p. i 



