on Alcohol at common Temperatures. 47 



Glycolic acid would stand in the same i-elation to glycol, 

 C^ H^ 0^, as glyoxylic acid to sethyle-glycerine, or acetic acid to 

 common alcohol : — 



Alcohol . C2 H^ 

 Acetic acid C^ H^ 0'-^ 



Glycol . . C^HSQ^ 

 Glycolic acid C^ H" 0^ 



^thyle-glycerine C^ H^ 0^ 

 Glyoxylic acid . C^ H'^ 0" 



Glycerine, C^ H^ 0^, should be produced from propylic 

 alcohol as sethyle-glycerine is formed from common alcohol ; 

 and the glycerine should yield wich nitric acid an aldehyde, 

 C^ H^ 0^, and an acid, C^ H^ 0"*, homologous with glyoxal and 

 glyoxylic acid. The results of my experiments on this point 

 and on the other substances formed by the action of nitric acid 

 on common alcohol, C^ H^ 0, will be communicated in a future 

 Number of this Magazine. 



Tartaric, citric, and malic acids, which occur frequently in 

 nature, accompany each other so often, that from this fact alone 

 one would suppose some similai-ity in their constitution. I have 

 shown on another occasion, that if glyoxylic and tartaric acids 

 are regarded as bibasic, their radicals are polymeric. Thus — 



C2 H2 0^ 0\ GlyoxyUc C* H^ 0^ . 01 Tartaric 

 H H .OJ acid, H H .Oi ^^id, 



or C^ H^ 0^, added to the formula of glyoxylic acid, would give 

 that of tartaric acid, — 



Difference. 



Glyoxylic acid . . C^ H'' 0^ ^2 ^2 q2 



Tartaric acid . . . CH^O^ 



Other connexions have also been pointed out between these 

 two acids. The same difference in composition shows itself 

 between glycolic, malic, and citric acids : — 



Difference. 

 Glycolic acid . . C^H'^O^ C^H^O^ 



Malic acid . . . C^H^O^ 



pa TJ2 02 

 Citric acid . . . CSH^O^ ^ ^^ '-' 



Or if we adopt for the radical C^ H^O^ the symbol (Gly), we 



get,— 



(Gly) 1 1 110 = Glycolic acid, 



(Gly)2 HHO = Malic acid, 



(Gly)3 HHO = Citric acid. 



