280 Hutton. 



2nd. That we know of no set of igneous rocks that 

 can be proved to be of generally older origin than the 

 earliest stratified deposits, but that they may often be 

 proved to be of posterior origin. 



3rd. That the stratified masses were formed from 

 the waste of pre-existing rocks, mingled with organic 

 exuvice. 



4th. That such strata afford a measure of the amount 

 of pre-existing land destroyed to afford materials for 

 their formation. 



5th. That there may be a progressive formation of 

 rocks in the bottom of the sea, contemporaneous with 

 great and repeated alterations of lower strata, that 

 approach the regions of internal heat (metamorphism). 



6th. That all strata being derivative, and a ma- 

 chinery existing capable alike of erecting and destroy- 

 ing rocks, in the whole course of visible nature ' we find 

 no vestige of a beginning no trace of an end.' 1 



1 In these modern days very few persons read Hutton, and those 

 who trouble themselves about old geology are in general more familiar 

 with Playfair's delightful ' Illustrations of the Huttonian Theory ' 

 than with Button's great original work, in which the philosophy of 

 igneous, stratigraphical, and metamorphic geology was described in 

 a manner that excited the admiring wonder of a few who in those 

 days were able to appreciate his generalisations. One of these was 

 the celebrated Dr. Black, Professor of Chemistry in the University 

 of Glasgow, who thus wrote to the Princess Daschkow. ' In this 

 system of Dr. Hutton there is a grandeur and sublimity by 

 which it far surpasses any that has been offered. The boundless 

 pre-existence of time and the operations of nature which he 

 brings into our view, the depth and extent to which his imagina- 

 tion has explored the action of fire in the internal parts of the 

 earth, strike us with astonishment. And when we consider the 

 view he gives us of a great river, such as that of the Amazons, 

 descending in a thousand streams from the country of the Andes, < 

 and forming those immense and level plains through which it flows 

 in a great part of its course, the mind is expanded in contemplating 



