336 



ON THE PLACE OF FISH IN 



Oxidation. 



It may giva 

 rise to light 

 or not. 



Without Oxygen animal life as it now exists on 

 this planet would be impossible, and every one, 

 whether they know the fact or not, has had life 

 maintained by Oxygen from the earliest moments of 

 their existence. 



The word that is used to express union with Oxygen 

 is OXIDATION. It is the oxidation of the elements 

 of which coal is composed that gives rise to the heat 

 and light of a fire. Oxidation appears to always 

 give rise to heat. In some cases the heat is so 

 slight it requires delicate instruments to detect it, in 

 some it can be readily observed, while in many cases 

 it is so great it gives rise to light. Very familiar 

 cases of oxidation are those which give rise to much 

 light the oxidation for example which occurs in 

 lamps and candles. Here the substances oxidized 

 are purposely selected in consequence of their rapid 

 oxidation producing light. 



This depends upon the rate of oxidation. Slow 

 oxidation frequently accumulates so much heat that 

 after a while light and flame are produced, and this 

 not unfrequently occurs in places, as for example in 

 hay-ricks and cotton factories, where such rapid 

 oxidation is not desired. 



Because the word ." burning " is so commonly used 

 for those cases of oxidation which give rise to light, 

 some writers, for the sake of avoiding the unfamiliar 

 word, speak of all oxidation as "burning." So long 

 as a definite meaning is kept to, it is entirely a ques- 

 tion of words, but if "burning" is used instead of 

 " oxidation," then it must be applied to such a case 

 as the oxidation of iron, which is commonly called 

 " rusting," and to similar cases where oxidation does not 



