11 4 Researches on the Constitution of the Fatty Substances, hy 



From which results the formula C-o Hg,, O^, which was 

 atlopted by Berzelius and most other chemists; and the 

 acid being bibasic, the formula for the anhydrous acid was 

 C70 Hg- O5. As, however, in organic analyses the hydrogen is 

 valued a little too high, Liebig proposed lately the formula 

 C70 Hgg O5. In order to decide upon the constitution of these 

 bodies, M. Redtenbacher commenced a complete investigation 

 of them at Liebig's request. 



The result was that the stearic acid was found, by a careful 

 series of analyses executed on it in its hydrated condition, and 

 on a great variety of its salts, to be represented in its anhy- 

 drous condition by the formula Cgg Hgg O5, and when hydrated 

 by Cgg Hgg O5 + 2 Aq ; the latter is composed of 



Carbon 77-04"] 



Hydrogen .... 12'58 WOO-0 

 Oxygen 10-38 J 



with which the numerous experimental results perfectly 

 agreed. 



Among other collateral evidence was the analysis of stearic 

 aether, which was found to consist of C^g H^^ O7, being pro- 

 duced by 



1 atom of Stearic acid Cgg Hgg O^ 



1 atom of iEther . . C^ H5 O \Q^^ H-g O, 



1 atom of Water . . HO 



The substance described by Lassaigne as stearic aether, 

 could not be formed. 



When stearic acid is distilled, there is generated a large 

 quantity of margaric acid and other products, with which 

 Chevreul did not occupy himself (margarone, &c.), and the 

 first full explanation of the process is due to M. Redten- 

 bacher. 



The formula of hydrated margaric acid hitherto generally 

 received was C70 HggOg, which was such that this acid might 

 be looked upon as a compound of 



1 atom of Stearic acid C^q Hgg O^ 



1 atom of Oleic acid Cyg Hg., O7 



2 atoms of Water ... H^ O.^ 

 Berzelius suggested also that a carbo-hydrogen, C-g Hg^^ , 



may be supposed to be the common radical of the stearic 

 and the margaric acid, which would then differ only in having 

 different degrees of oxidation. The composition of the mar- 

 garic acid has, however, been determined afresh by Varren- 

 trapp, with the following results. 



Margaric acid, whether prepared directly from human fat or 

 by the destructive distillation of tallow, lard, oleic acid or 



I 



