Researches on the Constitution of the Fatty Substances, 113 



formed ; at least the results of the analysis of a salt thus ob- 

 tained showed no definite composition*. 



Before concluding this paper it may be interesting to men- 

 tion a few facts connected with the butter of nutmegs. It has 

 been already stated, that when this butter is digested with 

 alcohol of the common strength, a soft fat of a I'ed colour is 

 dissolved : when this fat is distilled with a large quantity 

 of water, a colourless oil passes over. This has an agreeable 

 pungent odour, and is probably the same as that described by 

 John and others. 



But if this red fat be subjected to dry distillation, several 

 interesting compounds are formed, which, however, have 

 not been examined more closely. The same oil passes over 

 as that obtained by distillation with water, but as the heat in- 

 creases it is accompanied by a white crystalline fat, which 

 after being purified presents the characters of paraffin. A 

 black matter like humus remains in the retort, and may be 

 easily saponified by continued digestion with caustic potash ; 

 when the soap thus formed is dissolved in water, and de- 

 composed by muriatic acid, a mixture of fat acids is sepa- 

 rated. By dissolving this in weak alcohol, and allowing it to 

 evaporate, a black fat exactly similar in appearance to humus 

 is deposited. Upon further evaporation a white fat is likewise 

 separated, which may be purified by repeated solutions in 

 alcohol, and digestion with animal charcoal. The black fat 

 is soluble in alcohol and aether; with the latter it forms a 

 solution of a syrupy consistence. This solubility in aether 

 shows that it is not humic acid. The colour of the acid does 

 not appear to be merely accidental ; but the examination of 

 these substances was not proceeded with, for being products of 

 decomposition and not at all crystalline, there were no means 

 of ascertaining when they were sufficiently pure for analysis. 

 St. Andrews, Oct. 28, 1840. 



F 



XXI. Abstract of recent Researches on the Coyistitution of the 

 fatty Substances, made by MM, Redtenbacher, .Var- 

 RENTRAPP, Mayer and BROMEisf. 



ROM the original analyses ofChevreul, the composition 

 of hydrated stearic acid appeared to be 



Carbon 77-42~| 



Hydrogen . . . 12-43 WOO. 



Oxygen 10-15 J 



♦ Sericate of copper inay be obtained by double decomposition ; it is of 

 a green colour, insoluble in water, and contains water in cheniical con)bina- 

 tion; the scricates of zinc, lime, cobalt, S..'c. may be [)rocurcd in a similar 

 manner, but their examination was quite unnecessary. 



+ From the Annaten dcr Pharmacic,h\\y, August, and September, ]840, 



Phil, Mag. S. 3. Vol. 18. No. 115. Feb, 1841. I 



