tobacco

n. the dried leaves of the plant Nicotiana tabacum and other Nicotiana species (native to tropical America), which are smoked, chewed, or sniffed for their stimulant effects. The main active ingredient is nicotine. The leaves also contain volatile oils, which give tobacco its characteristic odor and flavor. Tobacco was used by the native tribes of North and South America when the first European explorers arrived and was quickly transplanted to gardens and plantations throughout the world. It has no therapeutic value but is of great commercial and medical importance because of its widespread use and associated detrimental cardiovascular, pulmonary, and carcinogenic effects. Indeed, smoking tobacco cigarettes was first identified by the U.S. Surgeon General in the 1960s as a major preventable cause of death and disability.

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Psychology term of the day

October 11th 2024

method of difference

the second of the five canons of empirical science laid down by John Stuart Mill. It is meant to establish sufficient conditions for a phenomenon. For example, if under one condition, C1, an effect, E1, does not occur, and as C1 is changed to C2 the effect E1 does occur, it may be concluded that C2 is a sufficient cause of E1, and the alternative hypothesis, that C1 causes E1, can be eliminated. Thus, the effect is attributed to the “difference” between conditions C1 and C2. Also called difference canon.