322 Ancient Vegetation of the Earth. 



inhabitants ; and the vegetable kingdom, at that period, main- 

 tained undivided sway over all the undelnged portions of the 

 earth ; upon which it seems to have been called to play another 

 part, in the economy of Nature. 



We cannot doubt, in truth, that the immense mass of carbon 

 accumulated in the bosom of the earth, in a state of coal, and 

 which is the product of the destruction of those vegetables which 

 grew at that ancient epoch, upon the surface of the globe, has 

 been imbibed, by those vegetables, in the carbonick acid of the 

 atmosphere — the only form under which carbon, not derived from 

 the destruction of preexisting, organized beings, can be absorbed 

 by plants. 



Now, a proportion, even very feeble, of carbonick acid, in the 

 atmosphere, is generally an obstacle to the existence of animals, 

 and particularly of the most perfect classes of them, as mammif- 

 ers, and birds ; while, on the contrary, this proportion is highly 

 favourable to the growth of vegetables : and if we admit that 

 there existed a proportion very much greater of this gas in the 

 primitive atmosphere of our globe than the present atmosphere is 

 found to contain, we may consider this one of the principal causes 

 of the powerful vegetation of these ancient epochs. 



This collection of vegetables, so simple, so uniform, and which 

 would consequently have been so little fitted to furnish suitable 

 aliment for animals of diversified structure, such as those existing 

 at the present day, in purifying the atmosphere of the carbonick 

 acid which it then contained in excess, would have prepared the 

 conditions necessary to a creation more varied : and if we still 

 wish to indulge that sentiment of pride which has caused man to 

 assLune that all in nature has been created exclusively for him, 

 we may suppose this primitive, vegetable creaiion, which prece- 

 ded, by so many centuries, the appearance of man upon the earth, 

 was, in the economy of nature, designed to prepare the atmos- 

 pherick conditions necessary to his existence, arid at the same 

 time to accumulate those immense masses of combustibles which 

 his industry was in future time to apply to his necessities. 



But, independently of this difference in the nature of the 

 atmosphere, which the formation of these vast depots of fossil 

 carbon renders extremely probable, may not the nature of the 

 vegetables themselves, that have produced them, furnish some 

 data upon the other physical conditions to which the surface of 



