POISONOUS DRUGS 185 
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 
Fig. 174, I.—Coea (Erythroxylon Coca, Coca Family, Erythroxylacee). 
5 Flowering branch. Leaf. (Baillon.)—Shrub about 2 m. tall; leaves 
whitish green below; flowers yellow; fruit scarlet. Native home, Peru. 
Fic. 174, I1.—Coca. Flower-bud. Flower, entire. Same, cut vertically. 
(Baillon.) 
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 
