^236 Natural Historxj. [Chap. III. 



geological theories, we are by no means to ima- 

 gine that httle has been usefully done in this de-^ 

 partment of natural history. Amidst all the splen- 

 did rubbish with which it has been incumbered, 

 5ome precious treasures have been brouglit to light. 

 Amidst the speculations which have darkened coun-^ 

 sel^ large additions have been made to our 

 knowledge of this important subject. These 

 may be briefly summed up in the following par- 

 ticulars. 



The materials for the formation of a correct and 

 rational theory of the earth have been greatly aug- 

 :piented during the last age. Enlightened mine- 

 ralogists, practical miners, and patient chemical 

 experimenters, have been engaged, throughout the 

 ^.-entury, in making accurate observations ; in visit- 

 ing foreign countries ; in exploring the bowels of 

 the eartli ; in comparing the strata of every portion 

 of the globe ; in examining their form, direction, 

 extension, and connexion ; in analysing their com- 

 ponent parts ; and in collecting a multitude of 

 facts, wliicli have all tended to throw light on the 

 €>rigin and history of our planet. By means of the 

 useful discoveries which these inquirers have made, 

 we are furnished with weapons for beating down 

 false theories, and with information enabling us to 

 pursue our investigations further, and with mare 

 advantage. " In this magnificent display of the 

 internal arrangement of the globe,'* says Mr. Kir- 

 wan, "many philosophical observers acquired distin- 

 guished eminence from tedious^ laborious, painful, 

 but successful exertions. Tilas^ Gmelin, Cronstedt, 

 Terber, Pallas, Charpentier, Born, Werner, Arduin,o^ 



