3. East Indian opium has a strong, empyreumatic smell, but not much of the peculiar, narcotic, heavy odour of the Turkey opium. The taste is more bitter, and equally nauseous, but it has less acrimony. It agrees with the Turkey opium in its other sensible qualities, except that its colour is blacker, and its texture less plastic, although it is as tenacious. It is more friable, and when triturated with water no insoluble, plastic residuum is left, but it is altogether taken up; eight parts in twelve being dissolved, and the remainder suspended in the fluid. Very little of it is brought to England, its consumption being confined to China and other oriental countries.

The aqueous solutions of both kinds of opium are transparent when filtered, that of the East Indian having the deepest brown colour; both redden litmus paper; neither is decomposed by alcohol, but both are precipitated by solution and tincture of iodine, the carbonates of potassa and of soda, by pure ammonia, and by chloride of barium: precipitates are also formed by solutions of the bichloride and nitrate of mercury, the acetate and diacetate of lead, the nitrate of silver, the sulphates of copper, of zinc, and of iron : by infusion of galls, and all astringent vegetable infusions: the precipitate, as Dr. Duncan justly observes, resembling more that produced by cinchonin than that by gelatine.1 The acetate of baryta does not alter the solution of Turkey opium, but it produces a copious precipitate with that of the East Indian: oxalic acid precipitates both, but the latter more copiously.

Edinburgh New Dispensatory, 5th edit. 332.

No article of the Materia Medica has occupied the attention of chymists so much as opium. I shall detail the more important results of their labours; but I may preface this account by stating, that from the experiments to which it has been submitted, the components of opium appear to be an oily matter, gum, bassorine, resin, bitter extractive; Jive peculiar crystallizable salts, namely, morphia, narcotina, codeia, meconina, narceia; two new acids, the meconic, and one not yet named; sulphates of lime and of potassa, alumina, and iron. The salt of potassa appears to be very abundant in the East Indian opium: the Turkish contains, besides, a species of gluten, and a substance resembling caoutchouc.

According to Bucholz, the proportion of extractive, in 100 parts of opium, is 35.6; of gum 30/4; of resin 9; gluten 11.4; substance like caoutchouc 4.8;1 sulphate of potassa 2, and of sulphate of lime 1; the remainder consisting of an oily or balsamic matter and waste. For a long time nothing more was known: but, as the narcotic power of opium evidently could not depend on any of the above-named principles, some others were to be looked for; and were at length discovered. Derosne, in 1803, asserted that the activity of opium depends on a peculiar salt. He evaporated a watery infusion of opium to the consistence of syrup, and digested the gritty precipitate formed by this evaporation in hot alcohol: as the solution cooled, a salt formed, which by repeated solutions and crystallizations was obtained free from the resin, of a white colour, and in rectangular prisms with rhomboidal bases: these were inodorous, insipid, insoluble in cold water, but soluble in 400 parts of boiling water; soluble in 100 parts of cold, and 24 of boiling alcohol; soluble in hot ether and the volatile oils, but separating as these fluids cooled; and very soluble in all the acids. Given to dogs, it produced the effects of a strong dose of opium; but these were readily relieved by vinegar.

In repeating the experiments of Derosne, I obtained a much greater proportion of crystals of this peculiar salt from East Indian than from Turkey opium, which I conceived to militate against his idea of its being the sedative principle, inasmuch as larger doses of that variety of opium than of the Turkey are required to produce its narcotic effect on the system. I had then no opportunities of ascertaining the power of this salt; but some experiments by M. Orfila1 demonstrated that, although it exerts a deleterious effect on the animal economy, yet that the symptoms differ from those produced by opium; and even from Derosne's account, it is not so powerful a narcotic as opium itself.2 My scepticism on this subject was further confirmed by the discovery of M. Serturner, of Eimbeck in Hanover. The first experiments of this chymist were made public about a year after those of Derosne; but they excited little attention until he published a second memoir in 1817. According to Serturner, the salt of Derosne is not the narcotic principle of opium; that principle being, according to him, an alkaline salt, which is combined with a peculiar acid in opium, but which he obtained in a separate state.

This salt he named morphium, and the acid he named meconic3 Robiquet confirmed the statements of Serturner regarding the existence of morphia4; and its narcotic properties are now generally known. The following are the chief modes which have been employed to procure the salts of opium.

1 Polletier ascertained the composition of the caoutchouc to be,-Carbon, 87' 89 + Hydrogen 15' 11 = 100 : and that of the oily matter, - Carbon, 72' 39 + Hydrogen 11.83 + Oxygen 15.78= 100.-Ann. de Chim, el Phys., i. 197.

1 Nouveau Journ. de Med. torn. x. p. 154.

2Annates de Chimie, Ixv. 270.

3Mr. Donaldson, surgeon, Stonehaven, is of opinion that the magisterium opii of Dan.Ludwig, noticed in his Dissertationes de Pharmacia, the second edition of which was published in 1688, was morphia. It was obtained by dissolving the opium in an acid, and precipitating by an alkali.-Edin. Journ. of Med. Science, vol. i. p. 476. Vauquelin has claimed the discovery of morphia and meconic acid for Sequin, who read a paper to the French Institute, on the salt of opium, in 1804; but Serturner, who made his discovery at the same time, went farther than Sequin.

4 Annales de Chimie et de Phys, t. v. p. 276.