ARTIFICIAL FORMATION OF FAT. 247 



fluence of the rays of the sun. It is interesting to remark that to these 

 same binary bodies do the fats return after accomplishing the successive 

 stages of their metamorphosis in the economy of animals. From car- 

 bonic acid and water they come ; to carbonic acid and water they return. 



But the origin of the fatty substances of animals is by no means so 

 clear. One of the questions which have been debated in chem- ~ 

 ical physiology is, Do animals collect from their food all the collect or fab- 

 fat they require, or have they the power of making it for them- ricate at - 

 selves ? In the preceding chapter, under the description of the origin of 

 the butter of milk, we have, in part, anticipated the facts which might 

 here be presented. Referring, therefore, to what has there been said, it 

 will be sufficient now to admit the general conclusion that fats and oils 

 very abundantly occur in plants. 



But instances are not wanting which show that from other sources 

 than the vegetable kingdom, and by processes very different to those ex- 

 ecuted by plants, fats may be made from substances in which they did 

 not pre-exist. We select some of these which have been offered by chem- 

 ists who have asserted the power of the animal system for such a form- 

 ation of fat. 



1st. When an animal body is buried under certain circumstances, it 

 does not undergo putrefaction, but changes into a fatty or soapy gu oged Jn 

 substance, adipocire. Attention was first directed to this fact stances of its 

 on the occasion of exhuming many bodies from the cemetery formatlon - 

 of Innocents in Paris. Those which lay a certain depth beneath the 

 ground were found to have undergone the change in question ; but that 

 it does not altogether depend on the condition of the earth of the grave, 

 as respects moisture or other such physical state, I have myself had the 

 opportunity of verifying in the case of a subject which had been buried 

 for nineteen years, and which was disinterred in a condition of perfect 

 preservation, so far as exterior appearance went, but which had been 

 wholly converted into adipocire. Yet, from the same burying-ground, 

 many other bodies were disinterred, but none had undergone a like change. 



2d. When nitric acid is made to act on fibrin apparently deprived of 

 its fat, an oily substance is disengaged. 



3d. During the action of nitric acid on starch, in the preparation of 

 oxalic acid, a like effect takes place, oily matter being set free. 



4th. As has been described in a preceding chapter, butyric acid may be 

 prepared from sugar, through the influence of casein, in the presence of 

 carbonate of lime. 



Though the conversion of albumenoid bodies into fat has not thus far 

 been distinctly accomplished in an artificial way, no doubt Production of 

 can exist that it is possible. Indeed, the experiments of fat from aibu- 

 Quain and Virchow respecting the origin of adipocire have menoid bodies - 



