OF FOOD. 107 



derived, under these circumstances, either directly or indirectly 

 from saccharine matters. But saccharine matters alone are not 

 entirely sufficient. M. Huber 1 thought he had demonstrated that 

 bees fed on pure sugar would produce enough wax to show that 

 the sugar could supply all that was necessary to the formation of 

 the fatty matter of the wax. Dumas and Milne-Edwards, however, 

 in repeating Huber's experiments, 2 found that this was not the case. 

 Bees, fed on pure sugar, soon cease to work, and sometimes perish 

 in considerable numbers; but if fed with honey, which contains 

 some waxy and other matters beside the sugar, they thrive upon 

 it ; and produce, in a given time, a much larger quantity of fat 

 than was contained in the whole supply of 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 

 the composition of the food in order to maintain the animals in a 

 good condition ; for pigs, fed on boiled potatoes alone (an article 

 abounding in starch but nearly destitute of oily matter), fattened 

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

 with a greasy fluid fattened readily, and accumulated, as mentioned 

 above, much more fat than was contained in the food. 



The apparent discrepancy between these facts may be easily ex- 

 plained, when we recollect that, in order that the animal may become 

 fattened, it is necessary that he be supplied not only with the 

 materials of the fat itself, but also with everything else which is 

 necessary to maintain the body in a healthy condition. Oleaginous 

 matter is one of these necessary substances. The fats which are 

 taken in with the food are not destined to be simply transported 

 into the body and deposited there unchanged. On the contrary, 

 they are altered and used up in the processes of digestion and 

 nutrition ; while the fats which appear in the body as constituents 

 of the tissues are, in great part, of new formation, and are produced 

 from materials derived, perhaps, from a variety of different sources. 



It is certain, then, 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 the oily 

 matters may sometimes be produced in the body from the sugars, 



1 Natural History of Bees, Edinburgh, 1821, p. 330. 



2 Annales de Chini. et de Phys., 3d series, vol. xiv. p. 400. 



