Tobacco - Poisonous Alkaloids

Tobacco consists of the dried leaves of the tobacco plant (Fig. 173) which have been previously submitted to a process of curing or fermentation. During this process is developed a peculiar volatile substance to which the aroma of the tobacco is mainly due. The chief active constituent is the alkaloid, nicotine (C₁₀H₁₄N₂), one of the most virulent of poisons. A single drop of pure nicotine will kill a dog. Smaller animals are killed by a whiff of its vapor. A child of eight died from an application to the scalp of juice expressed from fresh tobacco leaves. Medicinally, tobacco is used mainly for its quieting effect in certain nervous affections, but it is now rarely prescribed. No other plant, however, is so widely used as an indulgence. It is estimated that over 800,000,000 people habitually smoke or chew tobacco, or take snuff. The effect of tobacco upon the user varies with differences of age, temperament, and manner of living. Thus an amount of indulgence which does not seem to have any ill effect upon the health of a man of middle age and phlegmatic temperament who leads an out-of-door life, is found to be plainly harmful to a young man, particularly one of nervous or excitable temperament, and especially if he leads an indoor life. Whether when taken in moderate amount by persons of mature years, tobacco is always injurious, is a question with regard to which medical opinion is divided. All competent observers, however, are agreed that unrestrained use invites serious ills, produces enfeebled digestion, heart disease, and nervous debility, and may lead to insanity. Furthermore, all are agreed that even in very small amount, tobacco in whatever form is decidedly injurious to young persons, and that habitual use of it may quite unfit them for happy, vigorous life. It is a significant fact that those who are in training for athletic contests are forbidden to use tobacco.

Fig. 173.-Tobacco (Nicotiana rustica, and N. Tabacum, Nightshade Family, Solanaceoe). A, Turkish tobacco (N. rustica), flowering top. B, flower, entire. C, same, cut vertically. D, Virginia tobacco (N. Tabacum), flowering top. E, flower. F, pod, opening for discharge of seeds. G, seed. H, same, cut vertically. J, stigma, (v. Wettstein.)- Turkish tobacco, an annual growing about 1 m. tall; leaves glutinous; flowers yellowish or greenish; fruit dry. Native home, South America and Mexico.-Virginia tobacco similar to the Turkish but growing 2 m. tall; flowers rose or purplish. Native home, South America.