RESPIRATION. 357 



organs. The discharge, too, appears to be in proportion 

 to the air that is respired ; the same whether the solution 

 be performed through the operation of lungs or of gills, 

 and whether these belong to an elephant, a whale, a 

 water insect, or a mite. 



Whatever may be the mysterious principle, or fact, 

 or whatever we may name it, that we call life, and which, 

 like the mind of man or the Maker of the universe, 

 can be seen and known only in that which it does, there 

 is in the functions of life, a wonderful resemblance to 

 the operation of fire as combustion, they are both a 

 consuming, and carbonic acid, charcoal united with 

 oxygen, is produced ; and the production of that sub- 

 stance is in both cases in proportion to the intensity of 

 the operation. In the dormant animal there is little 

 consumption of oxygen and production of acid, just as 

 there is in the smouldering fire ; and violent muscular 

 exertion is accompanied by a correspondingly increased 

 consumption of oxygen and production of acid. Before 

 results are so uniformly the same, we are warranted in 

 concluding, that there must be some uniformity in the 

 process ; but in what that consists, the present state of 

 information does not enable us to say. 



In these remarks we have rather diverged from the 

 simple assertion, the truth of which we were led to 

 question ; but still they are proofs of the uniformity of 

 the laws upon which nature acts, and should lead us 

 not to receive as truth any departure from that uni- 

 formity, of which the fact and the reason have not 

 been carefully observed. That should teach us, that 

 when we cannot find a reason for the fact, which yet 

 seems a violation of the observed laws of nature, we 





