Juniperus Lycia. Gummi-resina.
Olibanum.[[582]]
Qualities. Form, fragments of a translucent, whitish yellow, and generally powdered with a whitish dust, occasioned by the friction of the pieces against each other; Odour, when burning is fragrant; Taste, bitterish and acrid. Solubility. When triturated with water, a milky solution results, which after some time deposits the resinous part, and retains not more than three-eighths dissolved. Alcohol dissolves three-fourths of it, and forms a solution perfectly transparent. Æther dissolves more than half, leaving a white opaque residuum soluble in water. Chemical Composition. The latest analysis of this substance is by Braconnot, who found in 100 parts of it, of volatile oil 8, resin 56, gum 39, and of an anomalous principle resembling gum, but insoluble in water and alcohol, 5·2 parts. The oil, in colour and smell, very strongly resembled that of lemons. Med. Uses. It is now less used than formerly; it is however stimulant and diaphoretic. Pulverized it enters into several popular electuaries for gleets, fluor albus, &c. and very probably acts by finding a passage into the urine, without undergoing any change or decomposition.
OPIUM. L.E.D. (Papaver Somniferum.) Capsularum immaturarum Succus concretus. (Turcicus.)
Turkey Opium.[[583]]
Two kinds are found in commerce, distinguished by the name of Turkey and East India Opium.
Qualities. Form, Turkey opium occurs in flat pieces, of a solid compact texture, and possessing considerable tenacity; Sp. gr. 1·336, so that, when compared with the condensed juices of other plants, it is heavy, being exceeded only in this respect by opoponax and gum-arabic. By long exposure to the air it becomes hard, breaks with a glimmering fracture, owing to the presence of a few saline particles, and affords a yellowish powder. It is opaque, tenacious, plastic, adherent to the fingers. Colour, a reddish-brown, or fawn. Odour, peculiar, heavy, and narcotic. Taste, at first a nauseous bitter, which soon becomes acrid with some degree of warmth. It is inflammable, but yields no narcotic odour on burning. Solubility. It is partially soluble in water, alcohol, æther, wine, vinegar, and lemon juice; when triturated with hot water, five parts in twelve are dissolved, six suspended, and one part remains perfectly insoluble and resembles gluten. By long boiling, its soporific powers are impaired and ultimately destroyed: the alcoholic is more highly charged with its narcotic principle than the aqueous solution; but spirit, rather below proof, is its best menstruum. The watery solution when filtered is transparent, and reddens the colour of litmus; it undergoes no change on the addition of alcohol, but precipitates occur from pure ammonia and from the carbonates of fixed alkalies; from the solutions of oxy-muriate of mercury, nitrate of silver, sub-acetate and acetate of lead, the sulphates of copper, zinc, and iron, and from an infusion of galls. Chemical Composition. Resin, gum, bitter extractive, sulphate of lime, gluten, Narcotine (see note) and a peculiar alkaline body, to which the soporific virtues of opium are owing, and to which the appropriate name of Morphia has been assigned; and it appears moreover that this new alkaline body exists in combination with an unknown acid, which has therefore been denominated the Meconic Acid; so that the narcotic principle of opium is Morphia in the state of a meconiate, or perhaps of a super-meconiate.
For these important facts we are indebted to the successive labours of Derosne,[[584]] Seguin,[[585]] Sertuerner,[[586]] and Robiquet. And the French codex contains, in its appendix, formulæ for the preparation of morphia[[587]] according to the directions of these two latter chemists: viz. Robiquet’s process. Three hundred parts of pure opium are to be macerated during five days, in one thousand parts of common water; to the filtered solution, fifteen parts of perfectly pure magnesia (carefully avoiding the carbonate,) are to be added; boil this mixture for ten minutes, and separate the sediment by a filter, washing it with cold water until the water passes off clear; after which, treat it alternately with hot and cold alcohol, (12, 22, Bé.) as long as the menstruum takes up any colouring matter; the residue is then to be treated with boiling alcohol (22, 32, Bé.) for a few minutes. The solution, on cooling, will deposit crystals of Morphia.
Rationale of the Process. A soluble Meconiate of Magnesia is formed, whilst the sediment consists of Morphia in the state of mixture, with the excess of magnesia; the boiling alcohol with which this residuum is treated, exerts no action upon the magnesia, but dissolves the Morphia, and on cooling surrenders it in a crystalline form. A repetition of the treatment with boiling alcohol will procure a fresh crop of crystals, and the process should be continued until they cease to appear.
Sertuerner’s method. It differs from the preceding, in substituting ammonia for magnesia, and in adding to the sediment, separated as before mentioned, as much sulphuric acid as is sufficient to convert the Morphia into a sulphate, which is subsequently decomposed by a farther addition of ammonia; the precipitate thus produced is then dissolved in boiling alcohol, which on cooling surrenders the Morphia in a state of crystalline purity. It appears however that the Morphia produced by this latter method, is less abundant and more impure and coloured, than that which is furnished by the process of Robiquet.