82 FOOD ACOESSOEIES 



efforts, make the total muscular energy produced less than 

 it would sometimes appear. 



Alcohol as a drug. — The real value of ordinary foods 

 depends not only upon their tissue building or energy 

 producing power but also upon their effect upon the 

 organs of the body. All nutrients affect the action of the 

 organs more or less directly, and their effects may be 

 beneficial or harmful according to the conditions or amounts 

 taken. In small quantities, the effects of alcohol are not 

 harnaful but in larger quantities it acts as a drug. A 

 drug is a substance which acts upon a special set of cells 

 either stimulating or retarding their natural action. As 

 a drug the effect of alcohol is ultimately to impede diges- 

 tion, dilate the blood vessels, cause loss of heat, and 

 destroy sensibility. In this respect it is like a powerful 

 narcotic, and to this narcotic action is due the bad effects 

 of large amounts. (See Narcotics, p. 86). 



Alcoholic beverages. — Alcohol is produced by a process 

 called fermentation (see p. 102) in fluids which contain 

 starches and sugars. In this process these two carbo- 

 hydrates (starch and sugar) are ultimately changed into 

 carbon dioxide and alcohol. The form of sugar which is 

 most readily changed into alcohol is what we have called 

 glucose (see p. 54). This glucose occurs abundantly in 

 the juices of many fruits, and especially in that of grapes. 

 Such juices naturally furnish one of the chief sources of 

 alcoholic drinks or beverages. Drinks made by the fer- 

 mentation of such fruit juices are called wines, and while 

 the term is frequently restricted to fermented grape juice, 

 it actually includes other fermented juices, such as cider, 

 blackberry wine, etc. 



Grains, potatoes, etc., are rich in starch. If a little of a 



