INTRODUCTION. 59 



tions, and his introduction of a number of new and precise 

 terms for stratigraphical purposes, marked an advance in the 

 study of the earth's crust scarcely less important than his 

 masterly classification of the rocks according to their mineral 

 constitution. 



Unfortunately, Werner's field observations were limited to a 

 small district, the Erz mountains and the neighbouring parts 

 of Saxony and Bohemia. And his chronological scheme of 

 formations was founded upon the mode of occuirence of the 

 rocks within these narrow confines. To him in that rich/ 

 mining district the minerals seemed all-important, and the 

 occurrence of organic remains fell into insignificance. Again,! 

 he held strong convictions that the ores preset in vfi nc C11 ^ ri ' 

 liiyeTsliaci separated out from supersaturated aqueous solution^ 

 of the metals, and he sought to explain in a similar way the 

 origin of the massive granitic and schistose kinds of rock. 

 The Wernerian doctrine was all the more attractive as it 

 seemed so simple. It taught that all the rocks of the crust, 

 like the earth's body" itself, had taken origin from aqueous , 

 solutions, either as chemical or as mechanical precipitates, 

 while volcanic lavas and scoriae represented rock-material that' 

 had been so precipitated but had subsequently been melted 

 and ejected. 



Werner was equally narrow in his ideas about the strati- 

 graphical relationships of the rocks. As a fundamental 

 principle he held that all varieties of rock had been deposited 

 in the same horizontal or tilted positions as they now occupy. 

 But strata inclined at an angle of more than 30 owed their 

 high inclination to local disturbances, such as the collapse of 

 crust-cavities, landslips, etc. These local inthrows and slips 

 exerted little influence upon the connection of the strata as a 

 whole ; rather, the successive deposits enveloped the earth 

 with the uniformity of the integuments of an onion. 



Werner gave little credence to the opinions of Pallas and 

 Saussure regarding the elevation of wide continental territories 

 and the upheaval of mountain-chains. Like De Maillet and, 

 Buffon, he ascribed the inequalities of surface conformationj 

 exclusively to the erosive agency of water, more especially to 

 the strong currents created during the retreat of sea-water after 

 its periodic inundations of the land. 



Similarly, with regard to the origin of basalt, he came into 

 conflict with the results obtained by the leading authorities on 



