INSTRUCTIVE NATURE OF THE SCIENCE. 40 



INSTRUCTIVE NATURE or THE SCIENCE. Geology has 

 this in common with the other studies of nature, that it 

 shows us the error of many of our early impressions, and 

 warns us to doubt the evidence of our senses, until proved 

 by scientific investigation. Thus, while Astronomy convinces 

 us that the sun, which rises in the east and sets in the west, 

 makes no revolution at all, but that it is the apparently 

 unmoving earth which really performs the daily round ; so 

 Greology commences her instructions with truths not less at 

 variance with our preconceived opinions. It unfolds the 

 fact, that the present condition of our earth, far from being 

 of primeval date and character, constitutes but one of the 

 numerous vicissitudes through which it has passed in the 

 course of its eventful history. The mountains which we 

 deem of antiquity coeval with the earth itself, the hills which 

 in our phraseology are " old," to a proverb, this science 

 convinces us are of very different dates, and have all, geo- 

 logically speaking, been elevated at comparatively modern 

 periods. Again, from the earliest times it has been the 

 habit of man to associate the idea of stability with the 

 land, and of fluctuation and change of level with the sea. 

 Greology, however, demonstrates the very reverse of this to 

 be true, and shows that while the land has undergone changes 

 and disturbances, and has been the scene of elevation and 

 depression, of intrusion and dislocation, the sea, from its 

 nature, as a fluid, has constantly maintained the same un- 

 altered level. The rocks, which we regard as having ever 

 been the hard, and unyielding objects which we behold them 

 now, by the external characters which they bear, by the 

 gentle impressions of organic structure which they present 

 by the tender foliage of the plant the delicate markings 

 of the shell science proves to have been thus imprinted 

 when their substance was soft, and by this means convinces 

 us that rocks were once in a state of sand or mud. These 

 are but a few of the instances which might be adduced of 

 the valuable and instructive discipline of a science which 

 rids us of errors and prejudices derived from early habit and 

 association, and implants in their stead more just and philo- 

 sophical ideas of nature, and her Divine Author. 



ANTIQUITY or THE EARTH. Thus while we are accus- 

 tomed to regard our planet as coeval with man, and as 



