236 MR HENRY HOW ON CERTAIN SALTS AND 
and hydrochloric acid are found in the liquid. Nitric acid rapidly decomposes it, 
with formation of hydrochloric, hydrocyanic, carbonic, and oxalic acids. Sub- 
mitted to destructive distillation it fuses and blackens, hydrochloric acid is evolved 
in large quantity, and towards the end of the process a small quantity of a crys- 
talline sublimate appears. This product I obtained in too small quantity to 
examine thoroughly. I imagine it, however, to be pyrocomenic acid, and attri- 
bute the presence of the traces of chlorine I detected to the impossibility of com- 
pletely purifying the little matter I had at my disposal. 
Chlorocomenic, like comenic acid, is bibasic, forming two series of salts. The 
salts I chose for controlling the analysis, and establishing the saturating power of 
the acid, were those of silver. 
Bichlorocomenate of Silver —A warm aqueous solution of the acid gives, with 
nitrate of silver, a white precipitate, in feathery crystals. When freed from the 
excess of solution of silver and nitric acid by washing with cold water, in which 
it is sparingly soluble, it may be recrystallized from boiling water, from which it 
separates on cooling in brilliant, short, prismatic needles. It is not at all, or very 
slightly, decomposed by boiling in water when no free nitric acid is present. The 
silver, in the following analysis, was determined by precipitation with hydro- 
chloric acid; the ordinary process of burning the salt and weighing the residuary 
silver being inapplicable, since a portion of the chlorine of the acid remains in 
combination with the metal upon ignition. 
{ 5*157 grains dried at 212° gave 



2:490 ... chloride of silver. 
Experiment. Calculation. 
SS 
Carbon, . : st 24-19 Ce 72 
Hydrogen, : os 0-67 H, 2 
Oxygen, . . oo 24-19 0, 72 
Chlorine, . , + 11:94 Cl 35'5 
Oxide of silver, 39-03 39-01 AgO 116-1 
100-00 100-00 297°6 
The composition of the salt, when dried at 212’, is therefore represented by 
the formula 
Ag0, HO, C,, {a } 0,. 
The crystallized salt appears to be a combination of the above with water, in 
the proportion of three equivalents of the latter to two of the former; the two 
specimens of the salt giving this indication were of different preparations. 
5-674 grains air-dry salt lost at 212° 
bios ... ‘water, 
5:428 grains air-dry salt lost at Bip? 
0253 ... water. 

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