“The modifications I would introduce are as follows:—
“a. The opium should be first treated with bisulphide of carbon or benzine.
“b. The dried residue should then be mixed with its own weight of lime and two or three times its bulk of some inert powder, such as pumice or glass. It is then to be percolated with water, the first part of the percolate being returned as fast as it runs through. By this means much less water will be required to exhaust the opium than would otherwise be the case.
“After the opium has been exhausted, which will be known by the liquid dropping through devoid of taste, the solution should be exactly neutralised with dilute sulphuric acid and filtered and the precipitate washed. The clear solution is then to be evaporated over a water bath until its bulk is about 1⁄2 an ounce, and again filtered if requisite, then ammonia is to be added in slight excess, and the liquid allowed to stand for 24 hours.
“The precipitate can then be collected, washed with ether and dried, and to the amount formed must be added the amount corresponding to the quantity of water used in precipitating and washing.
“The morphia obtained by this process is of a dull white colour, crystalline, perfectly soluble in alcohol, acids, and alkalies.”
5. (Prollius.) This is a very simple process and is said to give very exact results. It is as follows:—The opium is exhausted with 9 or 10 times its weight of spirit of 34 per cent. strength. Of the resulting tincture, 100 parts are well shaken with 5 parts of ether and 2 parts of solution of ammonia in a stoppered bottle, and then allowed to stand from 12 to 24 hours. The liquids separate slowly, and retain, partly in the ether, partly in the alcoholic liquid, the colouring matter, narcotine, and other crystallisable constituents of opium; while the morphia separates in crystals between the two layers, and finally sinks to the bottom. The fluid portion is decanted, the crystals are washed with diluted alcohol, dried and weighed.
6.[76] (Teschemacher.) In employing the following method the use of alcohol to extract the morphia is avoided, and meconic acid is separated at an early stage, which prevents the formation of a basic meconate on precipitation of the morphia. Two special reagents are required for this process; the one prepared by mixing 1 part of ammonia, sp. gr. 0·880, with 20 parts of methylated alcohol, and digesting in this mixture a large excess of morphine; this, when filtered, is termed “morphiated spirit;” the other, morphiated water, is water saturated with excess of morphine, and contains 0·04 per cent. of this alkaloid. 1000 gr. of opium are macerated for 12 to 24 hours in about 4000 grains of cold distilled water, together with 300 gr. of lead acetate, stirring the mixture from time to time. This separates the meconic acid as lead meconate, whilst the morphia is dissolved in the acetic acid set free.
[76] ‘Chemical News,’ xxxv, 47.
After this maceration the opium may be readily ground in a mortar to a paste, and so much more cold distilled water added, raising the pestle and mortar with successive portions of it as to fill with the mixture a measure = 20,250 grains of distilled water; experience has shown that the space occupied by the insoluble matters measures from 200 to 300 gr., so that the limit of possible error, by averaging and allowing 250 gr. for the insoluble portion, amounts to 0·05% in opium containing 10% of morphia. The mixture is to be filtered and 15,000 measured gr. = 750 grains of opium, of the clear solution, are to be evaporated to an extract on a water bath, and this residue to be drenched with 3090 gr. of boiling alcohol or methylated spirit, and the whole digested, with frequent stirring, for about 10 minutes.