Alcohol dissolves resin and caoutchouc, and all the alkaloids and their combinations, with meconic acid, &c.
Amylic Alcohol dissolves all the alkaloids, if they are in a free state, and it also takes up a little of the resin.
Ether, Benzene, and Carbon Sulphide do not dissolve the resin, and only slightly morphine, if free; but they dissolve the other free alkaloids as well as caoutchouc.
Acids dissolve all the alkaloids and the resin.
Fixed Alkalies, in excess, dissolve in part resin; they also dissolve morphine freely; narcotine remains insoluble.
Lime Water dissolves morphine, but is a solvent for narcotine only in presence of morphine.
Ammonia dissolves only traces of morphine; but narceine and codeine readily. It does not dissolve the other alkaloids, nor does it dissolve the resin.
§ 346. Assay of Opium.—The following processes may be described:—
Process of Teschemacher and Smith.—This process, with a few modifications, is as follows:—10 grms. of opium are as completely exhausted with proof spirit at a boiling temperature as possible. The resulting alcoholic extract is treated with a few drops of ammonium oxalate solution, and the solution is almost neutralised with ammonia. The solution is concentrated to one-third, cooled, and filtered. The filtrate is farther concentrated to 5 c.c., and transferred to a small flask, it is washed into this flask by 4 c.c. of water, and 3 c.c. of 90 per cent. alcohol; next 2 c.c. solution of ammonia (sp. gr. 0·960) and 25 c.c. of dry ether are added. The flask is corked, shaken, and then allowed to rest over-night.