TRANSITION ROCKS. Ill 



endeavour to shew, that those which constitute its principal 

 members, are similar in different districts ; and, finally, that 

 they are of an older date than Granite, which maintains the first 

 place in point of priority in the system of Werner. 



It is well known, that one of the principal arguments brought 

 forward by Dr Hutton, is drawn from the penetration of the 

 stratified rocks, by veins extending from the mass of granite, 

 which he considered as affording a decisive proof, of the subse- 

 quent formation of that rock. It must not, therefore, be sup- 

 posed, that I aim at any thing original in the above assertion, 

 or that I even wish to limit the term Alpine Schistus, as ap- 

 plied by that ingenious philosopher ; there can be no doubt, 

 that, under this name, he included both the Primitive and 

 Transition stratified rocks of Werner ; but in his time no di- 

 stinction had been drawn between them : it is only later disco- 

 veries that have imposed the necessity of more specific lan- 

 guage, which may at once account for that want of precision 

 by which his writings are so much obscured, and the deficien- 

 cy of mineral ogical knowledge, with which he has been so fre- 

 quently charged. 



Werner, in the construction of his systematic arrangement, 

 thought that he perceived grounds for considering all rocks, 

 from Granite down to Clay-slate, as bearing marks of having 

 been deposited from the original chaotic fluid, in a certain de- 

 terminate order. In them no detritus, or anything like organised 

 nature, was to be observed ; and to this point every rock re- 

 mained exactly in the same state, in which it was at the period 

 when it first acquired solidity. To these alone the title of 

 Primitive was attached. 



In the rocks immediately following, of which Limestone is 

 said to be the first, he remarked an essential difference ; the 

 limestone not only abounded in organic remains, but other 



members 



