
PRODUCTS OF DECOMPOSITION OF COMENIC ACID. 239 
rather less soluble in hot water and in alcohol than the former acid; it is de- 
posited from alcohol in fine rhombic crystals. It is decomposed by zinc. With 
nitric acid it gives hydrobromic, hydrocyanic, carbonic, and oxalic acids. 
The acid ammonia salt crystallizes in fine long needles; the acid salts of potass 
and soda also crystallize. I could obtain no neutral alkaline salts. The acid salts of 
the alkaline earths are very soluble; the neutral salts are insoluble and amorphous. 
The acid silver salt was obtained by adding warm aqueous solution of bromo- 
comenic acid to an aqueous solution of nitrate of silver; the flocky precipitate which 
fell was well washed with cold, and subsequently dissolved in boiling water. This 
fluid deposited the salt, on cooling, in brilliant, short, prismatic crystals. The 
silver was determined, in the following analysis, by solution of the salt in boiling 
water, and the subsequent addition of hydrochloric acid— 
{ 6:435 grains dried at 212° gave 
2678 --- chloride of silver. 
which, calculated for per-centage, gives 33°64 oxide of silver; the number 33-93 
being that corresponding with the formula 
Ag0, HO, C,, ea 0,. 
A neutral silver salt was also obtained as a yellow amorphous precipitate, by 
adding solution of the acid in slight excess of ammonia to nitrate of silver in 
excess; it presented, on drying, the clayey character I remarked in the corre- 
sponding salt of chlorocomenic acid. As there could exist but little doubt of its 
composition, I thought it useless to occupy time with an analysis of it. 
lodine appeared, from some experiments I made, to be without the power of 
decomposing comenic acid. 
Acid Comenic Ether. 
Comenovinic Acid.—From the bibasic nature of comenic acid, and a consider- 
ation of the fact that Dr Srennouse* failed in a special attempt to obtain a neutral 
ether of this acid, I was led to seek it in its combination with ether, a compound of 
an acid nature analogous to sulphovinic, tartrovinic, and the other acids similarly 
constituted. I did not succeed in my endeavour to form such a substance by 
action of sulphuric acid on alcohol and comenic acid; but was more successful 
in a slight modification of the method usually adopted for the production of 
organic ethers. Comenic acid in the state of fine powder was suspended in abso- 
lute alcohol, in which it is insoluble per se, and a stream of dry hydrochloric acid 
_ gas was passed through the fluid. After some time the whole or the greater 
part of the acid was taken up, the last portions disappearing very slowly. The 
clear solution gave no deposit, even on standing at rest for many hours, nor was 
any precipitate produced by the addition of water, but when it was evaporated to 
* Mem. and Proc. Chem. Soc., vol. i. 
