152 BRITISH PLANTS 
(c) Drugs.—Hundreds of drugs used in medicine are 
prepared from plants—poisons, antiseptics, narcotics, 
anesthetics, etc.—all capable of producing more or less 
profound disturbances in the physiological activities of 
the human body. Peruvian bark, or Cinchona, is the 
source of quinine, the opium-poppy the source of laudanum 
and morphia. Tobacco may be regarded as a mild drug. 
Industrial Economie Plants include such as provide 
timber, paper, straw, cane, fibres (cotton, jute, hemp, 
flax), gums, resins, oils (palm, olive, linseed), turpentine, 
pigments (madder, indigo, saffron, logwood, turmeric), 
camphor, rubber, and guttapercha. 
In fact, man is dependent upon the vegetable world for 
much of his food and drink, his luxuries, the materials 
to clothe him, and for countless products which serve 
directly or indirectly to satisfy his needs. 
Poisonous Plants.—Many plants contain principles 
which act as poisons to man. These poisonous substances, 
however, are not necessarily poisonous to all animals. 
Thus, the thrush eats the berries of the cuckoo-pint ; and 
every succulent fruit, however poisonous it may be to 
others, must be eaten with impunity by some birds (p. 136). 
Drugs are, in a sense, only mild poisons. The following 
plants, growing in England, have been used at one time 
or another in medicine: buckthorn, broom, cherry- 
laurel, hemlock, woody nightshade, foxglove, rhubarb, 
spurge-laurel, chamomile, gentian, valerian, dandelion, 
nettle, etc. 
Folk-lore has associated benignant properties with 
many plants which are quite innocent of any medicinal 
value, good or bad. Some possessed magical qualities, 
and were used in enchantments. 
