CENANTHYLIC ACID. 67 



Combinations* With the exception of the alkaline salts, most 

 of its salts are difficult of solution, generally resembling tablets of 

 cholesterin : moreover this acid has a strong tendency to form 

 acid salts. The baryta-salt crystallises in nacreous scales, which 

 are soluble in water and in alcohol. 



(Enanthylous acid, C 14 H 13 O 2 .HO, formerly also named 

 oenanthic acid, occurs combined with oxide of ethyl in various 

 fusel oils, especially in that of wine. Whether it be actually to be 

 regarded as a lower state of oxidation of oenanthylic acid, or as a 

 special acid, cannot at present be decided. 



(Enanthal, aldehyde of oenanthylic acid, C 14 H 14 O 2 , is obtained 

 by the simple distillation of castor oil ; like the other aldehydes, 

 when exposed to the atmosphere, it readily oxidises into the cor- 

 responding acid, and forms a compound (although somewhat 

 unstable) with ammonia. 



Preparation. This acid, which Laurent formerly discovered 

 amongst the products of distillation of the oils, and named azoleic 

 acid, is formed, together with other acids of this group, during the 

 decomposition of wax, oleic acid, and especially of castor oil, by 

 concentrated nitric acid. In using castor oil, however, we obtain 

 this acid unmixed with any others, so that we have only to combine 

 it with baryta, and recrystallise the salt, in order to obtain it in a 

 state of purity. 



Tests. As the baryta-salt of this acid separates from the mother- 

 liquid earlier than caproate of baryta, and more slowly than the 

 caprylate, and as, further, it crystallises in plates, while the two 

 latter salts form minute needles, which are grouped together so as 

 to have a wart-like appearance, we have a means of separating, at 

 least roughly, this acid from those which are most closely allied to 

 it. We cannot, however, be perfectly certain regarding its actual 

 presence, without an elementary analysis, or the determination of 

 its atomic weight. 



Physiological Relations. 



Occurrence. As has been already mentioned, this acid is only 

 of interest in relation to animal physiology, inasmuch as it is one of 

 the products of oxidation of the fats : and the observations which 

 were made regarding the occurrence of valerianic acid are here 

 equally applicable, except that oenanthylic acid is not produced 

 during the decomposition of nitrogenous complex atoms. 



P 2 



