S94 Observations on the Nature and Importance of Geology/. 



of this science are so framed, as, in some measure, to accommo* 

 date the incommensurability of nature to our capacity ; and by 

 connecting things that are homogeneous, they enable us to take 

 a survey of natural phenomena ; but, while we are occupied with 

 a single department, we become sensible of its dependence on 

 others, and are frequently at a loss to assign to each its peculiar 

 province. 



Of all the departments of physical science, geology is the niost 

 intimately connected with other branches, and stands in need of 

 their assistance, or assists them more frequently than any other. 

 This mutual relation, which contributes, in no small degree, to 

 bestow a peculiar charm on geology, has, at the same time, a 

 tendency to render it a difficult study. 



When speaking of Geology, it must be understood to compre- 

 hend Oryctognosy as its foundation ; the latter gives us a know- 

 ledge of the characters, the former of their combination. Who- 

 ever is in danger of mistaking one character for another, will 

 never learn to read accurately ; and he who continually devotes 

 his attention to nothing but the characters, may, indeed, owing 

 to the difficulty of recognising them, be very profitably engaged, 

 but he will be frustrated as to the ultimate and most essential 

 object of their study. 



The terrestrial globe, whose structure, so far as it is exposed 

 to our view, is the proper object of geognostic investigation, is 

 the extensive workshop wherein the powers of nature, with which 

 natural philosophy and chemistry are engaged, have operated, 

 and are still operating. It is not therefore matter of surprise, 

 though these two sciences have both a kindred affinity for geo- 

 logy, to which the latter is indeed so closely related, that geo- 

 logy may be considered as practical chemistry. In addition to 

 this, geology has, with other departments of science, many points 

 of contact, from which it may be allowable to select a single ex- 

 ample. 



Geometry, guided by simple principles, formed regular bo- 

 dies from limited plane surfaces, and determined their peculiar 

 properties, without foreseeing that models of them would be 

 found in nature herself; but since observation has brought us 

 acquainted with the regular figures of mineral bodies, they ex- 



