56 



ceeded to discuss the products of decomposition of comenic acid. He 

 first shewed that it readily undergoes oxidation by nitric acid, and 

 by solution of persulphate of iron, with the production of carbonic 

 and oxalic acids in both cases, and elimination of hydrocyanic acid 

 in the former. 



No change is produced by the action of sulphurous acid, or of 

 sulphuretted hydrogen. 



When chlorine acts upon comenic acid or solution of bicomenate 

 of ammonia, a new acid is produced, crystallizing in fine brilliant 

 square prismatic needles : analysis shewed the composition to be 



2H0,C„fS ]o« + 3HO. 



>'C..{S}^ 



The three atoms of water are expelled at 212°; in the formula of 

 the anhydrous acid, we have that of comenic acid, in which an equiva- 

 lent of hydrogen is i-eplaced by chlorine. 



This is a strong and bibasic acid, forming two series of salts : the 

 author, after detailing the properties and products of decomposition 

 of the acid itself, describes the appearance of some of these salts, and 

 gives the analysis of those of silver, wliose composition he shews to be 



For the acid, AgO HO, C^j ( ci ] ^« ^"^ 



For the neutral, 2 AgO, C^j I q. \ Og. 



The action of bromine is precisely similar, and furnishes an acid 

 of the same character, appearance, and properties : its formula is 



2HO,C,J?Jo, + 3HO. 



>.c.{l} 



It loses its water of ci'ystallization at 212°. 



Some account is given of the salts of bromocomenic acid ; and the 

 author then goes on to examine the action of hydrochloric acid gas upon 

 absolute alcohol holding comenic acid in suspension. He details the 

 process by which he obtains a substance which is evidently comeno- 

 vinic acid, analogous to tartrovinic, sulphovinic acid, and such bodies. 

 It has the composition 



HO, C^ Hg O, Cj2 H2 Og. 

 It has an acid reaction, coagulates white of egg, &c., fuses and sub- 



