CHAPTER IV 



STIMULANTS AND NARCOTICS 

 I. DEFINITIONS 



77. Stimulants. In the preceding chapter we discussed 

 food substances, and these, we learned, yield material for the 

 repair or growth of the body, or supply the fuel necessary 

 for producing energy in the body. But in addition to the 

 various nutrients that may be used for one or all of these 

 purposes, we often take with our food certain substances 

 that are not useful to any considerable extent in any of these 

 ways. As examples of such substances, we may mention 

 spices. Such substances add an agreeable flavor to our 

 foods, and so stimulate our appetites ; hence, they are known 

 as stimulants. A stimulant is any agent that temporarily 

 quickens some process in the body. The most common stimu- 

 lants are tea, coffee, and alcohol. 



78. Narcotics. Another class of substances that we 

 sometimes use has an effect directly opposite to that of 

 stimulants. Ether, morphine, and chloroform, for example, 

 do not quicken any process in the body as do stimulants, 

 but, on the contrary, lessen the degree of activity. Any 

 compound that acts in this way is called a narcotic. A 

 narcotic is any substance that directly induces sleep, blunts 

 the senses, and in sufficient amounts produces complete in- 

 sensibility. 



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