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XXII. On the Consolidation of the Strata of the Earth. By 

 SIR JAMES HALL, Bart. F. R. S. Lond. & Edin. 



(Read April 4. 1825J 



JL HE public attention, animated by scientific controversy, has 

 of late years been much directed to Geological subjects ; and 

 the certainty of many important facts, has in consequence been 

 ascertained beyond dispute, which were formerly unknown, or at 

 least involved in such obscurity, that no person could have ven- 

 tured to assert them, without being charged with extravagance. 

 But though, no doubt, many branches of this science still re- 

 main to be investigated, such inquiries may now be said to have 

 acquired a considerable degree of consistency and interest, from 

 the substantial basis upon which they have been found to rest. 



Thus, in the present day, it is universally admitted, that a 

 great part, I believe, in point of bulk, by far the greatest part, of 

 the solid rock which constitutes the external mass of our globe, 

 is stratified : that these strata, or at least a considerable por- 

 tion of them, have at one period consisted of a loose assemblage 

 of sand and gravel, broken from rocks of still higher anti- 

 quity : that these fragments are infinitely various in quality, in 

 bulk, and in form ; some retaining their original sharpness, 

 others rounded and polished by agitation in the water : that 

 these beds alternate with others of limestone, composed, in a 

 great measure, of the shells of sea-fish, which shells are also oc- 

 casionally scattered through the other strata. So that on the 

 whole, it seems to be ascertained to the satisfaction of all par- 



