234 MR HENRY HOW ON CERTAIN SALTS AND 
The salts of strontian somewhat resemble in appearance those of baryta, but 
are more soluble. 
It is curious that this acid does not form an acid salt with oxide of copper; 
the salt with two equivalents of base being obtained both by the addition of 
comenic acid itself and of acid comenate of ammonia to a solution of sulphate of 
copper. This salt was analysed by Srennouse, who also examined some others, 
the details of which will be found in the paper already referred to. 
Products of Decomposition of Comenic Acid. 
By Oxidation—The conversion of comenic into carbonic, oxalic, and hydro- 
cyanic acids, by the agency of nitric acid, was noted among the first facts con- 
nected with the subject. It takes place with very dilute acid. When tolerably 
strong nitric acid is employed, the action is very rapid and violent, and when once 
commenced by application of a gentle heat, is completed in very few minutes, 
though the heat be withdrawn. 
Dr Srennouss, in the paper before mentioned, states that when comenic acid 
is kept for some hours at a temperature of 150° Fahr. in a solution of persulphate 
of iron, yellow crystals are formed, which contain protoxide of iron, and an acid 
which is not comenic acid. I did not succeed in obtaining a similar result on a 
repetition of his experiment, possibly because the circumstances were not strictly 
the same. I think it possible, however, that these crystals consisted of oxalate of 
protoxide of iron, from the ease with which comenic acid is oxidized, when boiled 
in a solution of persulphate of iron. I treated a quantity of comenic acid in this 
way, effervescence of carbonic acid ensued strongly, and the fluid was found to 
contain much protoxide of iron and oxalic acid. I identified the latter by a pre- 
paration and analysis of its lime salt in a pure state, after the removal of the iron 
and sulphuric acid by appropriate means. 
I could not succeed in producing any change by the action of sulphurous acid 
or of sulphide of hydrogen upon comenic acid. 
Action of Chlorine on Comenic Acid. 
Chlorocomenic Acid—When a current of moist chlorine is passed through 
water holding powdered comenic acid in suspension, a portion of the acid is dis- 
solved, and the clear liquid deposits, after the lapse of some time, long, brilliant, 
and colourless prismatic needles of the new acid. The same effect is produced 
when a solution of the ammonia salt is employed, and as, from the more ready 
solubility of this substance, results were more conveniently obtained, I used it in 
preference in my experiments. 
If an alkaline ammoniacal solution of comenic acid be exposed to the action 
of chlorine, the first result is a precipitation of the acid comenate of ammonia ; 
but if a cold, saturated, coloured solution of the latter salt be employed, and the 
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