258 PHYSIOLOGY. 



effects. They all act on the nervous system. They pro- 

 duce a pleasurable effect or they bring relief from pain. 

 The use of many of them is begun during illness, when 

 they are administered to relieve pain, as in neuralgia. 

 The habit, once formed, is hard to break. Others, having 

 heard of the soothing effects of these drugs, are unwise 

 enough to experiment on themselves. Only the confes- 

 sions of such victims, and the degrading effects on char- 

 acter, show how powerful is the sway which this class of 

 drugs gains over those who yield to their influence. Let 

 no one flatter himself that he has a strong will and can 

 control himself. The history of their use is ever the 

 same. They enslave. They destroy. 



Tobacco. The use of tobacco is needless. Man gets 

 along well enough without it. It is injurious to many. It 

 is an expensive habit. Many a man spends enough on 

 tobacco to send a boy through college. With the excellent 

 cheap printing of to-day, many of the very best books may 

 be bought for the money that is paid for as many cigars. 

 Even for those who can abundantly afford it, it seems ex- 

 tremely selfish, when it is needless, and there is so much 

 good that might be done with the money. Another very 

 selfish feature is that so many men do not seem to con- 

 sider the fact that the air is public property, and they 

 have no right to fill the air with any gas or smoke that is 

 offensive to others. Very likely many men derive great 

 comfort from the use of tobacco after they have once 

 formed the habit, but most of these were made sick in 

 learning, showing that the use is unnatural. 



Nicotine. The active material in tobacco is a sub- 

 stance called nicotine. It is a violent poison. A drop of 

 it in concentrated form will kill a dog. 



