Cocaine is an alkaloid prepared from the erythroxylon coca, a shrub, five or six feet high, found wild in the mountainous regions of Ecuador and Peru, where it is also cultivated by the natives. The South American Indians, for centuries, have chewed coca leaves as a stimulant, but the highly poisonous principle, now called cocaine, to which the plant owes its peculiar effects, was not discovered till 1859. Within a few years this drug has come into favor as an agent to produce local anæsthesia, and has proved exceedingly valuable in surgical operations upon the eye and other sensitive organs. It has already, however, been diverted from its legitimate use as a benefaction, and to the other evils of the day is now added the "cocaine habit," which is, perhaps, even more dangerous and difficult to abandon than either the alcohol or the opium habit. PHYSIOLOGICAL EFFECT.--Applied locally, cocaine greatly lessens and even annihilates pain. Taken internally, it acts as a powerful stimulant to the nervous system, its physiological action being similar to that of theine (p. 170), caffeine, and theobromine. Used hypodermically, its immediate effect, says one to whom it was thus administered, is to cause "great pallor of countenance, profuse frontal perspiration, sunken eyes, enlarged pupils, lessened sensitiveness of the cornea and conjunctiva, lowered arterial tension, and a feeble pulse and heart beat. Under its influence I could not reason. Everything seemed to run through my brain, and in vain I summoned all my will power to overcome an overwhelming sleepiness." A few doses of this drug will in some persons produce temporary insanity. Used to excess, it leads to permanent madness or idiocy. "Cocaine," says a writer in the _Medical Review_, "is a dangerous therapeutic toy not to be used as a sensational plaything. If it should come into as general use as the other intoxicants of its class, it will help to fill the asylums, inebriate and insane." PRACTICAL QUESTIONS. 1. Why is the pain of incipient hip disease frequently felt in the knee? 2. Why does a child require more sleep than an aged person? 3. When you put your finger in the palm of a sleeping child, why will he grasp it? 4. How may we strengthen the brain? 5. What is the object of pain? 6. Why will a blow on the stomach sometimes stop the heart? 7. How long will it take for the brain of a man six feet high to receive news of an injury to his foot, and to reply? 8. How can we grow beautiful? 9. Why do intestinal worms sometimes affect a child's sight? 10. Is there any indication of character in physiognomy? 11. When one's finger is burned, where is the ache? 12. Is a generally closed parlor a healthful room? 13. Why can an idle scholar read his lesson and at the same time count the marbles in his pocket? 14. In amputating a limb, what part, when divided, will cause the keenest pain? 15. What is the effect of bad air on nervous people?