.Atropine.—Atropine is found iu the belladonna (Atropa belladonna), and in the roots of the Datura stramoaium. It is obtained from the latter by exhausting the roots with alcohol and adding milk of liine to the. solution. The liquid is filtered and saturated with a slight excess of dilute sulphuric acid ; it is then boiled till free from alcohol and precipitated with carbonate of potash, filtered and allowed to stand ; the atropine is deposited in fine, silky needles, and subsequently purified by frequent crystallization in alcohol. Care must be taken not to raise the temperature too high in these processes, as atropine is extremely volatile. It is slightly soluble in water, and con siderably so in alcohol and ether. It is very alkaline, and has an intensely hitter taste. It is used in medicine, in minute doses, a full one being about of a grain.
Brucine.—Brucine is contained in the St. Ignatius Ivan, and in the Strichnos nux vomica, along with strychnine. It is generally prepared from the latter plant, which is much cheaper. The powdered nuts are treated with very dilute, boiling sulphuric acid, and expressed. The acid is next saturated with excess of milk of lime, by which sulphates of lime, strychnine, and brueine aro thrown down. The precipitate is collected on a filter, and dried, and then treated with boiling alcohol, which dissolves the two alkaloids. The liquid is filtered while hot, and in cooling deposits the greater part of the strychnine. The bruciue remains in solution and may be obtained by evaporation. They are both purified by repeated crystallization in alcohol. Brucine is slightly soluble in water, freely soluble in alcohol, but insoluble in ether. It is alkaline, bitter, and very poisonous.
Cinchonine.—This alkaloid exists with quinine in most of the cinchona barks, and is obtained from them iu the same way as quinine (see Quinine). The mother-liquors containing sulphate of cinchonine, are precipitate with carbonate of soda, and the precipitate is digested in ether, which dissolves the quinine. The cinchonine is dissolved in alcohol, and the solution is decolorized with animal black ; it is next filtered and submitted to slow evaporation, when the cinchoninc is depo sited in quadrilateral crystals. Cinehonine is insoluble in cold water, but soluble in 2,500 parts of boiling water. It is alkaline and bitter, and like quinine, a febrifuge, though in a less degree.
Iforphine.—Morphine, or Morphia, is the moat important alkaloid obtained from opium. To obtain it, the opium is digested in tepid water, and strongly expressed several times. The solu
tion is new evaporated down with powdered carbonate of lime. When about the consistence of a syrup, water is added, and the precipitated meconate of lime is filtered off. The liquid is again concentrated at a gentle heat. When concentrated and quite cold, a solution of chloride of calcium and a little hydrochloric neid are added, end the mixture is left to stand for fifteen days. During this time crystals of hydrochloratea of morphine and codeine are deposited. In order to separate these, the crystals are dissolved in water, and treated with dilute ammonia, which precipitates the morphine, leaving the codeine in solution. The morphine is purified by repeated crystallizations in alcohol. When prepared in this way, morphine is often contaminated with a little narcotine, which may be removed by treating with ether in which morphine is quite insoluble. Morphine is vary slightly soluble in cold water, in boiling water it is more soluble, and still more so in boiling alcohol. It has no smell, but an intensely bitter taste, and has a powerfully narcolie action. It is used medicinally in very miuute doses as a sedative. In larger doses it is extremely poisonous.
otiffine.—Quiuine is, perhaps, on account of its tooio and febrifuge properties, the most im portant alkaloid known. It exists with cinchonine and other substances in tho bark of tho cinchonas, The bark is powdered, and boiled several times with sulphuric, or hydrochloric acid ; after each boiling it is carefully expressed, and afterwards the liquors are mixed together. The quinine, ciuchoninu and some impurities are precipitated with earbouste of soda, and the precipi tate is collected in a cloth, compressed, dried, and digested with alcohol. The solution is next treated with dilute sulphuric acid, in sufficient quantity to exactly saturate the alkaloids, after which the alcohol is removed by boiling. The liquid is now allowed to cool, wheu the quinine is deposited as sulphate in crystals. The einchonine, which is more soluble, remains in the mother liquors. The crystals of sulphate of quiuiue are dissolved in alcohol, and the solution is decolorized by the addition of a little animal black ; they are subsequently purified by recrystallization. If the mother-liquors still contain quinine, they are precipitated by carbonate of aodapand the precipi tate is re-dissolved in sulphuric acid. The sulphate of quinine is separated by repeated crystal lizations. Pure quinine may be prepared from the sulphate by precipitating it with a mineral alkali.