GENERAL SCIENCE 



per cent of the alkaloids. But in these small amounts 

 it is well known that they greatly affect the nervous 

 system. 



Tea and coffee have practically no food value, but 

 cocoa contains some nutritious fats and carbohydrates 

 (starch and sugar) and so cocoa is the least harmful of 

 the three. But enough fats and carbohydrates can be 

 obtained from foods in which there is no stimulant. 



28. Narcotics. Narcotics are drugs which deaden 

 the nerve sense and usually hinder proper heart action. 

 In large doses they cause sleep. In any quantity, how- 

 ever small, they weaken brain 

 and muscular energy. For this 

 reason they should never be 

 taken except when given by a 

 competent physician. The three 

 common narcotics are nicotine, 

 alcohol, and opium in its vari- 

 ous forms. Boys contracting 

 the drug habit usually follow 

 these up in the order named. 



Nicotine. Nicotine (CiaHu 

 N2) is the narcotic found in 

 tobacco. It is a colorless liquid 



and is such a strong poison that one drop of it will kill 

 a dog. Nicotine boils at a temperature of 476 F. (247 C) 

 and during the burning of the tobacco in smoking the heat 

 turns the nicotine into steam or vapor and it is then drawn 

 into the mouth, sometimes into the lungs, and a part of 

 it blown out through the nose. As soon as the smoke 

 gets into the mouth or lungs its temperature is lowered 

 and the nicotine soon condenses into the liquid form and 

 is then absorbed by the blood. Nicotine is the poison 



TOBACCO PLANT 



