Outlines of Geology. 79 



sent order of things rests, and how trivial a change would suffice 

 to obliterate all that now exists ; thus inspiring the well-attempered 

 mind, not with sorry fancies and idle fears, nor with that super- 

 stitious awe which sometimes results from gross ignorance, and 

 sometimes from perverted knowledge, but with deep and unshaken 

 admiration of that boundless wisdom which governs the revo- 

 lutions of nature — which. 



Builds life on death, on change duration founds. 

 And bids the eternal wheels to know their rounds. 



II. 



Having noticed some of the leading subjects of geology, and 

 briefly enumerated some of the hypotheses entertained by our 

 precursors in this department of physico-chemical science, I shall 

 proceed more particularly to explain its objects, as they are now 

 pursued, and endeavour to sketch an outline of the study, as it 

 exhibits itself at the present day. & 



Its first and leading object is to become practically licquainted 

 with the present state of the Earth's external structure ; for, 

 excepting of its crust or rind, we know nothing ; and all that has 

 been suggested, either by theory or experiment, relating to its 

 internal composition, its density, and the constitution of the en- 

 tire mass, is mere surmise and guess-work — deductions hastily 

 drawn from superficial observation, or unwarranted inferences 

 from imperfect researches. - 



The present surface of our planet is composed of lapideous 

 materials, the nature and composition of which, it is the business 

 of mineralogy and of chemistry to determine ; not that the minutiae 

 of either of those studies need, of necessity, be gone into by the 

 geologist, for the substances which thus present themselves are, 

 comparatively, few in number and simple in their nature, and 

 their external characters and intimate composition are soon 

 learned ; yet, if he would pursue his subject under every advan- 

 tage, and extend his inquiries into its more refined departments, 

 he must neither be a superficial mineralogist, nor an imperfect 



