128 The Founders of Geology LECT. 



the mineral matter that was introduced into them could 

 only come from above. He drew no distinction in this 

 respect between what are now called " mineral veins " and 

 "intrusive veins." Veins of granite, of basalt, of por- 

 phyry, of quartz, of galena, or of pyrites were all equally 

 chemical precipitates from an overlying sea. He does not 

 appear to have seen any difficulty in understanding how 

 the desiccation and rupture of the rocks were to take place, 

 if the sea still covered them, or how, if they were exposed 

 to the air and evaporation, he was to raise the level of the 

 ocean again so as to cover them, and fill up their rents 

 with new precipitates. 



Werner's original scheme of classification of the rocks 

 of the earth's crust had at least the merit of clearness and 

 simplicity. Though he borrowed his order of sequence 

 partly from Lehmann and Fuchsel, he worked it into 

 a scheme of his own regarding the origin of the rocks 

 and their successive production from a universal ocean. 

 Tracing in the arrangement of the rocks of the earth's 

 crust the history of an original oceanic envelope, finding in 

 the masses of granite, gneiss, and mica-schist the earliest 

 precipitations from that ocean, and recognizing the suc- 

 cessive alterations in the constitution of the water as 

 witnessed by the series of geological formations, Werner 

 launched upon the world a bold conception which might 

 well fascinate many a listener to whom the laws of 

 chemistry and physics, even as then understood, were but 

 little known. Unfortunately the conception was based 

 entirely on the imagination, and had no real foundation 

 in observation or experiment. 



Werner adopted the leading ideas of his system in an 



