Nicotia'na Tabac'um, Tabacum, Tobacco. -- The commercial dried leaves, U.S.P. 1820-1890: C. And S. America (cultivated). Coarse robust annual, 1-2 M. (3-6 degrees) high; stem erect, unbranched, solid, green, hairy; root long, fibrous; flowers rose-color, calyx bell-shaped, hairy, viscid, corolla 4-5 Cm. (1 3/5-2') long, tubular, inflated; fruit ovate capsule, 2.5 Cm. (1') long, opening at summit; seed many, reniform, reticulate, brownish. Leaves, about .5 M. (20') long, 10-15 Cm. (4-6') wide, ovate-lanceolate, acute, entire, waved, brown, friable, hairy; odor heavy, peculiar; taste nauseous, bitter, acrid. Plant not known to be wild, and leaves in curing undergo a sweating process (chemical change) by which odor is modified through generation of a new volatile principle, and amount of nicotine decreases owing to its volatility; contains nicotine .7-5-11 p.c. (colorless oily liquid), nicoteine (nicotia) 2 p.c., nicotelline, nicotimine, pirolidine (?), nicotianin (tobacco camphor), tannin, resin, gum, malates, citrates, ash 14-18-27 p.c. (Ca, K, NH-- phosphates, sulphates, malates, chlorides, nitrates); solvents: alcohol, hot water.  Narcotic, sedative diuretic, emetic, myotic, diaphoretic, cathartic, antiseptic; first stimulates (causing convulsions) then paralyzes motor nervous system (spine), produces vomiting, purging, collapse, contracted pupils, depressed then increased heart action (rapid, feeble pulse), cold extremities, death by paralysis of respiration and heart; excessive use causes dyspepsia, diminished sexual power, nervousness, angina pectoris, and in the young impairs body nutrition.  So severe as to be little employed as a medicine, but may be used to relax spasms, relieve local pain, constipation, spasmodic asthma, tetanus, as an enema in intussusception, strangulated hernia, impacted cecum, hemorrhoids, scabies, strychnine poisoning.  Poisoning: By tobacco or nicotine, give tannin, emetics, then strychnine (physiological antidote), alcohol, ammonia, digitalis, belladonna, iodides, artificial respiration, maintain recumbent position; tobacco heart (cardiac irregularity and palpitation) -- abandon use.  The toxic effect of tobacco smoke is mostly due to nicotine, but there are present collidine, pyridine, picoline, ethylamine, acids, etc.  Dose, gr. 1/2-3 (.03-.2 Gm.); wine (vinum), 10 p.c., mv-60 (.3-4 cc.); enema tabaci, 5 p.c.; Oleum Tabaci, U.S.P. 1850-1870 (from distilling leaves -- acrid, poisonous, dark brown oil liquid); aqueous extract, fluidextract, infusion, ointment, poultice.  N. Rus'tica, Wild Tobacco, and N. Quadrival'vis, Canada, E. United States.  N. Repan'da, Cuba.  N. Per'sica, Persia.  N. Rustica, cultivated in Turkey, India, etc.  All may be used similarly.