"And again, tobacco is not for the body, neither for the belly, and is not good for man, but is an herb for bruises and all sick cattle, to be used with judgment and skill."[A] Although tobacco has been used for several centuries by civilized man, the real cause of the effect which it has upon the human body was not understood until the early part of the last century. In 1809, a chemist separated from tobacco an active principle, in an impure state, some of the properties of which he observed. In 1822, two other chemists succeeded in isolating the same principle, in a pure condition, and found it to be a colorless, oily liquid, of which two to eight per cent is found in all tobacco. This substance has been called nicotine; later investigations have shown it to be one of the most active poisons known. Tobacco owes its activity entirely to this poison."[B] [Footnote A: Doctrine and Covenants, 89:8.] [Footnote B: Wormley, Micro-chemistry of Poisons, 2nd ed., pp. 434, 435.] The intensely poisonous nature of nicotine is illustrated by a number of cases on record. One drop placed on the tongue of a cat caused immediate prostration, and death in seventy-eight seconds. A smaller drop was placed on the tongue of another cat, which resulted in death after two minutes and a half. A third cat to which a similar quantity had been administered was dead after seventy-five seconds. A man who was accustomed to smoking took a chew of tobacco, and after a quarter of an hour accidently swallowed the mass. An hour later he became unconscious and died. In another case, in which an ounce of tobacco had been swallowed, death resulted in seven hours. In still another case, one ounce of tobacco was boiled in water, and the solution drunk as an remedy for constipation. The patient died in three quarters of an hour.[A] These, and numerous other cases, illustrate the intensely poisonous nature of tobacco. The evil effects of the repeated use of small amounts of tobacco, in smoking or chewing are also well understood. [Footnote A: Ibid, pp. 436, 437.] [Sidenote: Joseph Smith probably did not know the poisonous nature of tobacco in 1833.]