FOOD ACCESSORIES AND DRUGS 305 



habit. Among the most valuable remedies at the physician's 

 disposal is opium or its active principle, morphine, which 

 possesses remarkable power to produce insensibility to pain. 

 It sometimes happens, however, that by incautiously using 

 this drug for this purpose men and women become addicted 

 to the habit. They finally cannot do without the drug, and 

 its constant use causes an appalling moral and physical de- 

 generation ; so far indeed does this often go that the victim 

 will commit crime in order to obtain the drug. It should 

 be clearly understood that it is unsafe for anyone to use 

 opiates to relieve pain; indeed, these should never be used 

 except when prescribed by a careful physician. 



23. Chloral, cocaine, etc. Men and women may become 

 slaves to the use of other drugs and in much the same 

 way as they become slaves to alcohol and morphine. Among 

 these drugs are chloral and cocaine. They belong in the 

 same general group of hypnotics or anesthetics, and the 

 habit acquired is perhaps no worse than the opium habit. 

 It is certainly very little better. Let the student remember 

 that the root of the evil here, as elsewhere, is the substitution 

 of the use of the drug for normal habits of healthful living. 



24. Tobacco. The physiological effects of tobacco are quite 

 complicated, so complicated that it is difficult to make 

 general statements with regard to them. The effects of 

 chewing are quite different from those of smoking, and 

 those of smoking, no doubt, vary according as the smoke 

 is or is not drawn into the lungs (inhaled). 



The leaf of tobacco contains a poison (nicotine) which 

 exerts a powerful action on the heart and on nerve cells. 

 It is not, however, proved that the bad effects of the use 

 of tobacco are due entirely or even chiefly to this substance, 

 but it unquestionably contributes to the physiological effects. 



The smoke from tobacco also contains ammonia vapor 

 which locally irritates the mucous membrane of the mouth, 

 throat, nose, etc., and this irritating action at times acts. 



