344 THE HUMAN BODY. 



activity, indirectly as well as directly; these experimenters 

 find that it not only takes oxygen from the tissues, but 

 so influences them as to diminish their power of using 

 what it leaves. We may conclude that under ordinary 

 circumstances alcohol is of no use as an energy-yielding 

 food; although, since it is oxidized in the body, it would 

 act as a real food to a starving man; or to a very sick per- 

 son who might be unable for the moment to absorb and 

 digest other substances. 



As regards tissue-formation, alcohol cannot build up 

 proteid material, since it contains no nitrogen; and proteid 

 material constitutes the essential part of muscular, gland- 

 ular, and nervous tissues. There is even some evidence that 

 alcohol leads to excessive waste of such tissues : several 

 competent observers have found that its use increases the 

 amount of nitrogen waste excreted from the body. The 

 only tissues whose formation alcohol seems sometimes to 

 increase are fatty and connective tissues; and we shall pres- 

 ently learn that in most cases the superabundance of these 

 tissues is deposited in places where it does harm. 



The study of alcohol as an article of diet leads therefore 

 to the result that (though a physician may find it useful as 

 a medicine in a crisis of disease when the system needs 

 urging to make a special effort) it cannot fairly be regarded 

 as a food when taken by persons in good health and properly 

 nourished. 



The whip applied to a horse will arouse him to call on 



What general conclusions may be reached as to the value of alco- 

 hol as a food? 



What relation has alcohol to the formation and waste of proteid 

 tissues? Of fatty and connective tissues? 



When may a physician find alcohol a useful medicine? 



Illustrate the action of alcohol on the body by comparison with a 

 whip used on a horse. 



