FORMATION AND DEPOSITION OF FAT. 383 



rendered probable, indeed, by the few experiments that have 

 been made on the subject, that obesity increases the power 

 of resistance to inanition. 1 At all events, in starvation, the 

 fatty constituents of the body are the first to be consumed, 

 and they almost entirely disappear before death. As we 

 have already seen, sugar is never deposited in any part of 

 the organism, and is only a temporary constituent of the 

 blood. If the sugars and fats have, in certain regards', simi- 

 lar functions in nutrition, and if, in addition to the mechani- 

 cal functions of fat, it may be retained in the organism for 

 use under extraordinary conditions, it becomes very impor- 

 tant to ascertain the mechanism of its production and depo- 

 sition. 



The production of fatty matter by certain insects, in ex- 

 cess of the fat supplied with the food, was established long 

 ago by the researches of Huber, whose experiments were 

 fully confirmed by Dumas and Milne-Edwards. 3 A little 

 later, similar observations were made upon birds, by Persoz, 8 

 and upon birds and mammals, by Boussingault. 4 Some of 

 the experiments of Boussingault are peculiarly interesting, 

 as they were made upon pigs, in which the digestive appa- 

 ratus closely resembles that of the human subject. They 

 showed conclusively that, under certain circumstances, more 

 fat exists in the bodies of animals than can be accounted for 

 by the total amount of fat taken as food added to the fat ex- 

 isting at birth. In some very interesting experiments with 

 relation to the influence of different kinds of food upon the 

 development of fat, it was ascertained that fat could be pro- 

 duced in animals upon a regimen, sufficiently nitrogenized, 

 but deprived of fatty matters ; but the fact should be recog- 



1 See vol. ii., Alimentation, p. 26. 



8 MILNE-EDWARDS, Lemons sur la physiologic., Paris, 1862, tome vii., p. 653. 



3 PERSOZ, Experiences sur Fengrais des oies. Comptes rendus, Paris, 1844, 

 tome xviii., p. 245. 



4 BOUSSINGAULT, Reckerches experimentales sur le developpement de la. graissi 

 pendent V alimentation des animaux. Memoire* de chimie agricole ct de physiologic, 

 Paris, 1854, p. 105, et seq. 



