AND SOME OF ITS DERIVATIVES. 403 
Action of Heat on Meconate of Ammonia. 
. 
Comenamic Acid.—Some of the highly-coloured mother liquors of the purify- 
__ ing process, were retained at or near the boiling temperature for some hours, 
' ammonia being kept present in excess. The addition of hydrochloric acid to the 
cooled fluid caused copious evolution of carbonic acid, and when added in proper 
quantity, a considerable precipitate. By repeated crystallisations from boiling 
water, and the use of pure animal charcoal, the precipitated substance was 
obtained in colourless shining scales; the following is its analysis before being 
rendered absolutely pure :— : 


4:335 grains, dried at 212°, gave 
7-287 ... carbonic acid, and 
1:370 ... water. 
, 6-295 grains, burnt with soda lime, gave 
' 8-700... ammonio-chloride of platinum. 
Calculation. 
FE 
Carbon, : : 45:84 46°45 Cr 72 
Hydrogen, 3 ‘A 3°51 3:22 ' 5 
Oxygen, ; : ae 41:30 0, 64 
Nitrogen, : ; 8°67 9-03 N 14 
100-00 100-00 155 
The results of which are sufficient to shew this body to have the composition of 
comenamic acid; the characters and reactions of the acid left me no doubt as to 
its identity with that derived from comenate of ammonia under similar circum-_, 
stances. It may be considered as formed from the bibasic meconate of ammonia, 
in the presence of an excess of ammonia, by the elimination of two eq. carbonic 
acid, two of water, and one of ammonia, as in the equation 
HO, 2.NH,0, C,, HO,,=C,, H, NO, +NH, +2HO+2C0,. 
This offers a convenient source of comenamic acid, as very impure meconic acid 
may be employed. 
Action of Chlorine on Bibasic Meconate of Ammonia. 
A current of chlorine gas passed through some of the coloured mother liquor 
of the above salt deprived it of colour considerably, and caused a speedy deposit 
of hard granular crystals adhering to the sides of the vessel. This was collected, 
and recrystallised from boiling water; it was found to be not very soluble, and 
the fluid on cooling deposited the substance in hard crystals, which, on being mag- 
nified, were seen to consist of thick needles radiating from acentre. It contained 
no chlorine, and proved to be an ammonia salt of meconic acid containing one 
equivalent of alkaline base. I am not aware that this salt has been obtained 
before, I therefore subjoin an analysis of it. 

