Memoir on the Nature of fat Sulstances. 131 



from the acids. When distilled it passes into the receiver with- 

 out changing its nature, and leaves but a slight charry residue 

 in the retort. It enters into fusion at the temperature o{"54|° 

 R. ; white wax in its state of purity melts at the same degree 

 of heat, according toBostock. From the properties which we 

 have recognised in tliis substance, we cannot mistake it for a 

 distinct species of adipocire ; for it differs sensibly from that 

 which we have obtained by the action of sulphuric acid upon 

 suet, since the latter substance presents but a grainy crystalliza- 

 tion like bees'-wax, and which is besides a little more fusible. 



I now return to the waters which have served to wash the 

 greasv matter proceeding from the distillation of the nitric acid 

 on suet. These waters, when collected, deposited a flaky white 

 matter ; but as the liquor appeared still to retain a great deal 

 in solution, doubtless in consequence of the nitric acid which 

 existed m this liquor, it was evaporated to the consistence of 

 honey, which l)ecame very solid upon cooling. This residue well 

 washed with cold water, left nearly two grammes of a very white 

 flaky and not very soluble powdery the water which had been 

 used in the washing, kept in solution but a small quantity of 

 yellow uiatter, but no trace of oxalic acid. M. Vogel had like- 

 wise observed, that by boiling nitric acid with fat or with beef 

 suet, a wliite powder was formed upon cooling. M, Vogel con- 

 sidered it as mucous acid ; but the properties which it presented 

 to me do not permit me to adopt the conclusion of this respect- 

 able chemist. This powder, as 1 obtained it, is an acid of a 

 sourisb taste, but it has not the granulated and crystallized aspect 

 of mucous acid. When exposed to heat, it melts hke suet, and 

 is entirelv volatilized on a burning coal, giving out a white va- 

 pour. Wlien distilled in a small retort, this acid passes into 

 the receiver in the form of an oily liquid, which on cooling as- 

 sumes the consistence of wax, without however losing its acid 

 taste and other properties. 



Warm oil of olives dissolves this acid, and a part is precipi- 

 tated upon cooling: it is soluble in cold water but in small quan- 

 tities. Warm water has a much stronger action over it; and 

 when it is l^oiling, we may obtain a solution which upon cooling 

 goes into a white mass, in which we can distinguish no appear- 

 ances of crystallization. This acid dissolved in water precipitates 

 several metallic solutions; with the acetate of lead, it produces a 

 flakv vvhite precipitate soluble in weak acetic acid: it forms also 

 deposits in the nitrate of mercury and sulphate of iron. The 

 latter is of a reddish colour ; but it does not produce any change 

 in the nitrate of silver, the sulphate of manganese and the sul- 

 phate of copper, although it produces with oxide of copper a 

 jalt which is soluble but in a moderate degree, 



- I 2 When 



