511. TABACUM.—TOBACCO. The leaves of Nicotia'na taba'cum Linné. Off. U.S.P. 1890. Large, oval, or oval-lanceolate leaves, often 500 mm. (20 in.) long when entire, but they are more generally somewhat broken; brown; thin; friable; the glandular hairs, so thick on the leaves when fresh, are scarcely discernible; short-petiolate; odor peculiar, heavy, narcotic; taste strong, bitter, and acrid. Constituents: Nicotine, C10H14N2, nicotianine (a camphor), bitter extractive, salts, resin, etc. Nicotine is a volatile liquid alkaloid and a virulent poison; there is hardly any of it contained in Turkish tobacco; by heat it is decomposed, yielding various pyridine compounds, hydrocyanic and acetic acids, etc.; these pass off in the smoke; the chief of these compounds are pyridine (in smoke from pipes), collidine (from cigars), lobeline, coniine, piperidine, sparteine, trimethylamine, etc.
Preparation of Nicotine.—Concentrated infusion made with acidulated water is treated with KOH and shaken with ether. The ethereal solution is precipitated with oxalic acid; the oxalate of the alkaloid thus precipitated is dissolved in boiling alcohol; evaporate to a syrup, agitate with ether, and make alkaline with KOH. On fractional distillation the colorless, oily alkaloid remains. It is very unstable.
Narcotic, sedative, diuretic, and emetic. It is rarely used in medicine. Dose: ½ to 2 gr. (0.0324 to 0.13 Gm.). Oil of tobacco is a pharmaceutical product, official in the U.S.P. in 1870, obtained by destructive distillation of coarsely powdered tobacco; it is a tarry liquid of offensive odor. Considerable oil is obtained by distilling the leaves with water. It contains nicotine (a dark, oily liquid).