11 



astronomical* calculations show that a mass of burning 

 matter revolving for a succession of ages would assume 

 the shape pf an oblong spher.e, oblate or flattened at the 

 extremities of a presum.ed axis, the very shape of the 

 earth ; if new mountains have risen from seas, and 

 continents disappeared to give place to new seas ; if, 

 in connexion with all these vicissitudes, the physical 

 and the moral condition of nature has improved, what 

 let us ask here, results from these facts and indications? 

 Simply the truths of Geology — one of the most sub- 

 lime, because fehe most natural of sciences; gne whose 

 volume is the great globe itself, unfolding its noble 

 pages of granite and crystal, and metal, as if to dis- 

 close in characters of fire, the awful truths of nature, 

 and reveal to the present age their once incomprehen- 

 sible narrations. 



Such being the facts of Geology, such its evi^lences, 

 such its conclusions, such its lessons of wisdom, go 

 with me, if you please, through such further enquiries, 

 testing its principles and inferences, as bear upon the 

 plan and object of my discourse. 



1. You are told by this Science that in the first epoch 

 of the phenomena, the earth was surrounded by an at- 

 mospihere too dense for animal life. The first enquiry 

 prompted, is, Why should such an atmosphere exist 1 



Various substances, such as water, lead, sulphur, 

 mercury, and zinc, are easily reduced to an aeriform 

 state. We have many chernical affinities to prove, 

 that such substances must have existed in connexion 

 with the earth, during the period of its primitive revo- 

 lutions. Apply the chemical law, that the higher the 

 temperature, the more rapid the evaporation, and it is 

 evident, that the greater the heat of the surface of the 



