Miscellaneous. 



431 



that an Allwise Creator would have made the life of plants and ani- 

 mals dependent upon adventitious circumstances. And surely it cannot 

 be averred that the emission of carbonic acid from volcanic sources, 

 ■would be regulated by a direct interposition of a Divine Providence. 

 The vegetation of the globe did not at once spring into existence, but 

 was as slow in its progression, as that of animals ; so that during the 

 ages, when a scanty vegetation covered the earth, the cabonic acid must 

 have been constantly accumulating. And if, at its commencement, 

 there was sufficient carbonic acid for the wants of plants, in the course 

 of ages it must have been accumulated in much larger quantities. So 

 that even on this view we must admit, that the proportion in the air 

 could not be kept in any constant quantity. But we do not see any 

 strong reason to suppose that the original food of plants was evolved 

 from the bowels of the earth; nor can we discover any strong objection 

 to the hypothesis, that all the carbonic acid and ammonia from the 

 beginning of time, were original constituents of the atmosphere. The 

 nitrogen and oxygen of which the atmosphere consists were certainly 

 not evolved from the interior of the earth; and yet upon the same 

 grounds could this be affirmed, for nitrogen, like carbonic acid, is 

 evolved from the volcanoes of the present day. It is indeed difficult to 

 conceive from what stupendous magazines of carbon the carbonic acid 

 of the air was formed, or how hydrogen became united with oxygen to 

 form all the water which covers the earth, without the occurrence of 

 such dreadful explosions as would dash the present system of the 

 world to fragments. Such stupendous operations of nature are as yet 

 beyond the capacity of the human mind to fathom : just so with the 

 ammonia. If we cannot comprehend the mighty power which deprived 

 its elements of their elastic condition, we can only believe that that 

 power is as yet undiscovered. 



From all that has preceded we believe we are warranted in con- 

 sidering that the carbonic acid and ammonia in the air were original 

 constituents of the atmosphere ; and further, that in former ages, they 

 were present in much larger proportion than at the present time. 

 We have shewn that such an atmosphere would not be unsuitable 

 for vegetable life, although it would certainly prove destructive to 

 terrestrial animals. We have now to examine the economy of vege- 

 table animal life of former times. 



The first certain proofs of organic life occur in the grauwacke 

 series. It is certainly singular that animals occur in this series, 

 where plants are not found. These animals are not merely zoopbyta, 

 but conchifera. Still we cannot suppose that sea-weed did not exist 



