Characters of Morphia. When pure, it crystallizes in very fine, transparent, truncated pyramids, the bases of which are either squares or rectangles, occasionally united base to base, and thereby forming octohedra. It is sparingly soluble in boiling water, but dissolves abundantly in heated alcohol; and the solution is intensely bitter; in æther it is far less soluble. It has all the characters of an alkali; affecting test papers, tinged with turmeric or violets; uniting with acids, and forming neutral salts, and decomposing the compounds of acids with metallic oxides. It unites with sulphur by means of heat, but the combination is decomposed at the same instant; it is incapable of forming soap with an oxidized oil. It fuses at a moderate temperature, when it resembles melted sulphur, and like that substance, crystallizes on cooling; it is decomposed by distillation, yielding carbonate of ammonia, oil, and a black resinous residue, with a peculiar smell; when heated in contact with air, it inflames rapidly; the voltaic pile exerts but little action upon it, yet, when mixed with a globule of mercury, the latter appears to become increased in bulk, and to change consistence. When analyzed by means of the deutoxide of copper, it yields carbon, hydrogen, and oxygen; and if ammonia has been employed, as a precipitant in its preparation, we shall also obtain some nitrogen, but not if prepared according to the improved process of Robiquet. Its habitudes with different bodies have not hitherto been sufficiently investigated, but they are highly important, in as much as they will explain the operation of those various medicinal compounds, into which opium enters as a principal ingredient. Sertuerner has given us an account of the effect of the alcoholic solution of Morphia on himself and three of his pupils; he found, that repeated small doses of half a grain produced at first decided excitation; then weakness, numbness, and tendency to fainting; after swallowing vinegar while in this condition, violent vomiting was excited, profound sleep intervened in one delicate individual, and next day he suffered from nausea, vomiting, head-ache, anorexia, constipation, and heaviness (Ann. de Chim. et de Phys. T. v.) This case is sufficient to shew that although Morphia possesses the characteristic powers of opium, its strength is by no means commensurate with its supposed concentration. When uncombined it exerts little or no action in consequence of its insolubility. The following history of its saline compounds may be useful.
The Carbonate crystallizes in short prisms.
The Acetate in needles, very soluble, and extremely active.
The Sulphate, in arborescent crystals, very soluble.
The Muriate, in plumose crystals, much less soluble; when evaporated, it concretes into a shining white plumose mass on cooling.
The Nitrates, in prisms grouped together.
The Meconiate, in oblique prisms, sparingly soluble.
The Tartrate, in prisms.
Morphia is separated from the above combinations by ammonia.
Morphia is very soluble in olive oil, and according to the experiments of M. Majendie, the compound acts with great intensity; with extractive matter, it forms a compound which is almost insoluble in water, but very soluble in acids.