THE NERVOUS SYSTEM AND ORGANS OF SENSE 417 



In business and in the professions, the story is the same. The 

 abstainer wins out over the drinking man. 



Not alone in activities of life, but in the length of life, has the 

 abstainer the advantage. Figures presented by life insurance com- 

 panies show that the nondrinkers have a considerably greater 

 chance of long life than do drinking men. So decided are these 

 figures that several companies have lower premiums for the non- 

 drinkers than for the drinkers who insure with them. 



" Other Narcotics in Common Use. Narcotics are very widely used 

 by the human family for the relief which they give from pain or fatigue, 

 or for the direct pleasurable sensations which they impart. All are deadly 

 poisons when taken in sufficient quantities. Those most common (after 

 alcohol) are tobacco and opium. 



" It has already been shown that tobacco may affect unfavorably many 

 parts of the system, and is especially injurious to the young. It stimu- 

 lates in small quantities and narcotizes in larger ones, working its effects 

 directly upon the nervous system. Nicotine, the powerful poison found 

 in tobacco, affects the nerve cells, injures the brain, and leads especially 

 to weakness of the heart by interfering with its supply of nervous force. 

 Many cases of cancer of mouth and throat are believed to have resulted 

 from tobacco smoking. 



" Opium, for its benumbing influence upon the nerves, is used by large 

 numbers of persons, especially in Oriental lands. Its continued use de- 

 ranges all the digestive processes, disorders the brain, and weakens and 

 degrades the character. Like alcohol, it produces an intolerable craving 

 for itself, and the strongest minds are not proof against the deadly appetite." 



REFERENCE READING 

 ELEMENTARY 



Sharpe, A Laboratory Manual for the Solution of Problems in Biology. American 



Book Company. 



Davison, The Human Body and Health. American Book Company. 

 The Gulick Hygiene Series, Emergencies, Good Health, The Body at Work, Control 



of Body and Mind. Ginn and Company. 



Moore, Physiology of Man~and other Animals. Henry Holt and Company. 

 Ritchie, Human Physiology. World Book Company. 



ADVANCED 



Hough and Sedgwick, The Human Mechanism. Ginn and Company. See also 

 references given at the end of Chapter XXIII. 



HUNT. ES. BIO. 27 



