xxviii INTRODUCTION. 



idea of Mr. Werner's system concerning the formation of 

 such parts of this planet, as we can hope to observe, little 

 exceeding the three thousandth part of its semi-diameter. I 

 warmly subscribe to the sentiments of admiration which are 

 paid to Mr. Werner's superior talents in many branches of 

 mineralogy, a science infinitely indebted to his industry and 

 sagacity. I also acknowledge the truth of the apophthegm, 

 Natura fecit omnes judices, paucos artifices. But I regret, with 

 his most enlightened admirers, that the scene of his inquiry 

 has been too confined ; and that his view of the mountains 

 of Saxony has not been extended over the globe. After forty 

 Saussure's years of sedulous observation among the Alps, Saussure, who 

 difficulties. ^ e g an hi s labours with a view of forming a system, declares 

 that his hopes were frustrated ; and that he had met with 

 such unaccountable confusion that he could not venture to 

 propose a theory. Yet Saussure, to practical observations on 

 a far superior scene, added the advantages of learning, and 

 mathematical and meteorological science, which Mr. Werner 

 unhappily wants, and which would have corrected and greatly 

 improved his speculations. 



After describing the general appearance of the surface of 

 the earth, and the effects of water, he proceeds to consider 

 the structure of rocks, in their minute parts, and in their 

 general fabric ; the latter chiefly consisting of the stratified 

 structure, and that with seams, in which last he includes 

 Formations, columnar basalt. His grand doctrine of formations next 

 appears. When the mass is uniform, as in granite, gneiss, 

 limestone, the formation is said to be simple ; but when dis- 

 similar masses occur, as of coal and basalt, it is called com- 

 pound. When the formations consist of several substances 

 always found together, though in regions of different compo- 

 sitions, they are all called independent formations j but 

 when only associated, they are called subordinate. The uni- 

 versal formations are found all over the globe -, but partial or 

 anomalous formations are confined to particular spots. De- 

 Other terms, tached portions on the summits of hills are called caps j but. 

 when a part appears only on one side of a mountain, it is 





