124 BIOLOGICAL ASPECTS OF HUMAN PROBLEMS 



ing the nutritive materials of the body. This is, 

 however, not the only use of the oxidative function. 

 Many substances which the body admits to its 

 juices have a dubious quality in respect to health- 

 fulness, or even outspoken poisonous properties. 

 This is not inconsistent with their having food 

 properties and with their being attacked, like food, 

 in the processes of oxidation. A simple but illustra- 

 tive case is that of the fate of ordinary or ethyl 

 alcohol in the body. It is a common occurrence 

 for ethyl alcohol to gain admission to the human 

 organism in quantities far in excess of what may be 

 considered a harmless dose. The oxidizing mecha- 

 nism promptly converts the alcohol into acetic acid, 

 and this acid then takes the usual course followed 

 by acetic acid of whatever origin (as from foodstuffs) ; 

 that is, it is burned to the end products, carbon 

 dioxide and water. Here, then, we have an example 

 of a defense against a poison which consists merely 

 in ranging the poison in line with the treatment 

 accorded by normal cells to food products of similar 

 constitution. But while this oxidative defense suf- 

 fices for the disposal of some poisonous agents, it is 

 by no means an adequate defense against others. 

 For some poisons the cells provide a synthetic method 

 of detoxication; that is, a method by which they 

 bring about a union of the poison with a substance 

 supplied by the body, the result of the union being the 

 formation of a new substance much less injurious 

 to the body than either of the original substances. 



