Tabacum

Tobacco

Tobacco. Tabac, Fr.; Tabakblätter, Ger. The commercial dried leaves of Nicotiana tabacum Linné (Nat. Ord. Solana-ceae).

Infusum Tabaci

Infusion of tobacco ( 3 j—Oj). Dose, as an enema, oz ss— oz iv. (Not official.)

Oleum Tabaci

Oil of tobacco. (Not official.)

Unguentum Tabaci

Tobacco-ointment (oz ss— oz viij) (Not official.)

Vinum Tabaci

Wine of tobacco (oz j—Oj). Dose, τη v— 3 ss. (Not official.)

Composition

Tobacco contains a powerful alkaloid—nicotine-*-in combination with malic acid. It is an oily, colorless liquid, strongly alkaline in reaction. Its taste is hot and acrid, and its odor disagreeable and peculiar. It is contained in the dried leaves, in the proportion of about five per cent.

Tobacco also contains a peculiar camphor nicotianine.

Tobacco-leaves are rich in mineral constituents: potash, lime, nitrates, and phosphates. The vapor of tobacco "contains numerous basic substances of the picolinic series, and cedes to caustic potash, hydrocyanic acid, sulphureted hydrogen, several volatile fatty acids, phenol, and creosote" (Flückiger and Hanbury, Husemann). It does not contain nicotine. The oil of tobacco is an empyreumatic product, obtained by distillation.

Antagonists and Incompatibles

The caustic alkalies, tannin, and the iodides, are chemically incompatible. Strychnine is, according to Haughton, a true physiological antagonist. Ergot, digitalis, belladonna, ammonia, and alcoholic stimulants, antagonize the effects of tobacco on the heart and arterial system.

In cases of poisoning, the stomach should be evacuated by emetics or the stomach-pump, and tannin and the iodides should be administered. Ammonia and brandy are indicated to relieve the failing circulation. Subcutaneous injection of strychnine should also be resorted to, and, if necessary, artificial respiration.

Synergists

All of the motor depressants increase the effects of tobacco.

Physiological Effects

Tobacco is a severe and very depressing nauseant and emetic. It is locally an irritant to the mucous membrane, and produces burning pain at the epigastrium. It is also laxative even when smoked, and in considerable quantity by the stomach causes hypercatharsis. The emetic effect of tobacco is, doubtless, the product of three factors: its cerebral action, its local irritation of the gastric mucous membrane, and its specific emetic property. The secretions of the intestinal mucous membrane are increased, and the muscular layer is thrown into tetanic contraction, whence the catharsis which follows its administration. Applied to a wounded surface, tobacco produces the same effects.

Its active principle, nicotine—the salts of which are crystalline— diffuses into the blood with great rapidity. It corresponds, in the mode and intensity of its action, to prussic acid. In a case narrated by Taylor, a fatal result ensued in three minutes after a toxic dose. In another case death occurred in five minutes (M. Fougnies, poisoned by Count Bocarmé). When a lethal dose is administered to an animal, the action of the heart continues after respiration has ceased. Its cavities are usually found empty, or containing black fluid blood. Tobacco is not, therefore, a cardiac poison, and the depression of the circulation noted when full medicinal doses are administered is, doubtless, due to the interference with the pulmonary functions. Applied directly to the muscular tissue of the heart, nicotine does not impair its contractile power (Benham). The blood throughout the body is black and fluid; but, as agitation with oxygen restores its color, and as the blood-globules are unaffected, the condition of the blood is doubtless due to the arrest of oxygenation (asphyxia).

Trembling and clonic spasms are produced by lethal doses of tobacco. Its ultimate effect is paralyzing, but preceding the muscular relaxation and paresis there is in animals, and occasionally in man, a definite tetanic stage. Death ensues through its paralyzing action on the muscles of respiration. The end-organs of the motor nerves lose their excitability, next the trunks of the nerves, and then the spinal cord, but the muscular irritability is unaffected. The brain is not directly affected. Giddiness and delirium have been noted in cases of poisoning by tobacco, but these symptoms, as well as the insensibility which immediately precedes death, are no doubt due to the accumulation of carbonic acid in the blood. The pupils are contracted by tobacco, and, in fatal cases, are insensible to light.

There is considerable sweating, and the skin is cold and clammy in fatal cases. The temperature of the body is decidedly reduced (Tsches-chichin). The elimination of nicotine probably takes place by the kidneys. Very free urinary discharge, at all events, is produced by tobacco, and, reasoning by analogy, it may be supposed that this effect is due to the direct action of the nicotine on the Malpighian tufts and on the tubules of the kidneys.

When a lethal dose of nicotine has been taken, and the effects follow immediately, there may be none of the symptoms described above. In the case narrated by Taylor, the "deceased stared wildly; there were no convulsions, and he died quietly [in three minutes], heaving a deep sigh in expiring."