CRYSTALLINE CONSTITUENTS OF OPIUM. 367 












Wouter’s formula, C,, H, O,,, requires 4:30 per cent. of hydrogen, which is 
much too low for the experimental result. 
Opianic Ether.—According to WouLER, opianic ether cannot be obtained by 
the action of sulphuric or hydrochloric acids upon a mixture of opianic acid and 
alcohol. I have found the reverse of this to be the case, and obtained it by chance 
on one occasion when hydrochloric acid had been added to the alcoholic solution of 
the opianate of potash, which had been separated from the excess of carbonate in 
the preparation of the acid itself. It is obtained in the form of colourless needles 
which are insoluble in water, but dissolve readily in alcohol and ether. It melts 
under water, and also dry, at the temperature of 198° Fahr. Its analysis gave— 


5°615 grains of opianic ether gave 
12°325  ... —_ earbonie acid, and 
2982 ... waiter. 
Experiment. Calculation. 
OO 
Carbon, 4 A 59-86 60-50 C,, 144 
Hydrogen, . 5 5:90 5:88 TL 14 
Oxygen, : ¢ 34:24 33°62 OF 80 
100-00 100-00 238 
Hemipinic Acid.—By further evaporation of the solution which has deposited 
opianic acid, hemipinic acid is obtained, and it may be purified by several crystal- 
lisations. It is, however, in this case frequently more or less yellow-coloured, 
but may be readily obtained colourless, and is also effectually separated from any 
traces of opianic acid which may chance to adhere to it, by precipitating the solu- 
_ tion with acetate of lead, and decomposing the washed hemipinate of lead by a cur- 
- rent of sulphuretted hydrogen. The characters of the acid corresponded in all 
_ respects with Wouenr’s description, and the analysis gave the same results as his. 


5-445 grains of hemipinic acid gave 
10-603  ... carbonic acid, and 
2275 ... water. 
Experiment. Calculation. 
Carbon, ; : 53:17 53°14 C,, 120 
Hydrogen, . 4 4-64 4-49 H,, 10 
Oxygen, 5 ; 42°19 42°44 OF 96 
100-00 100-00 226 
It will be observed that the formula above given, C,, H,, O,,, is exactly double 
of that attributed to hemipinic acid by Wouter. The examination of some of the 
salts of hemipinic acid leave no doubt that it is a bibasic acid, and that its con- 
stitution is correctly expressed by the higher formula, which its relations to 
opianyl and opianic acid would also lead us to consider as extremely probable. 
VOL. XX. PART III. 5G 
