"6. Alcohol lessens the power to endure cold. This is true to such a marked degree that its use by persons accompanying Arctic expeditions is absolutely prohibited. Food, on the other hand, increases ability to endure cold. The temperature after taking food is raised. After taking alcohol, the temperature, as shown by the thermometer, is lowered. "7. Alcohol cannot be stored in the body for future use, whereas all food substances can be so stored. "8. Food burns slowly in the body, as it is required to satisfy the body's needs. Alcohol is readily oxidized and eliminated, the same as any other oxidizable drug." [Illustration: Experiment (by Davison) to show how the nicotine in six cigarettes was sufficient to kill this fish. The smoke from the cigarettes was passed through the water in which the fish is swimming.] The Use of Tobacco.--A well-known authority defines a narcotic as a substance "_which directly induces sleep, blunts the senses, and, in large amounts, produces complete insensibility_." Tobacco, opium, chloral, and cocaine are examples of narcotics. Tobacco owes its narcotic influence to a strong poison known as nicotine. Its use in killing insect parasites on plants is well known. In experiments with jellyfish and other lowly organized animals, the author has found as small a per cent as one part of nicotine to one hundred thousand parts of sea water to be sufficient to profoundly affect an animal placed within it. The illustration here given shows the effect of nicotine upon a fish, one of the vertebrate animals. Nicotine in a pure form is so powerful a poison that two or three drops would be sufficient to cause the death of a man by its action upon the nervous system, especially the nerves controlling the beating of the heart. This action is well known among boys training for athletic contests. The heart is affected; boys become "short-winded" as a result of the action on the heart. It has been demonstrated that tobacco has, too, an important effect on muscular development. The stunted appearance of the young smoker is well known. [Illustration: The amounts of alcohol in some liquors and in some patent medicines. _a_, beer, 5 %; _b_, claret, 8 %; _c_, champagne, 9 %; _d_, whisky, 50 %; _e_, well-known sarsaparilla, 18 %; _f_, _g_, _h_, much-advertised nerve tonics, 20 %, 21 %, 25 %; _i_, another much-advertised sarsaparilla, 27 %; _j_, a well-known tonic, 28 %; _k_, _l_, bitters, 37 %, 44 % alcohol.]