226 Proceedings of the Royal Physical Society. 



of rock-masseS; he introduced into their study a precision of 

 nomenclature such as had never before been attempted. The 

 rocks thus strictly defined were traced by him in what he 

 believed to be a certain order throughout his little domain of 

 Saxony; but, full of enthusiasm in his subject, he easily per- 

 suaded himself that what seemed to him to be the sequence 

 in that territory was the normal sequence for the whole globe. 

 His system of geognosy, being thus simple, and capable of 

 ready application elsewhere, soon acquired notoriety. It 

 saved labour in investigating the geological structure of a 

 country, since it assumed that, when once the true nature of 

 the rocks had been determined, a reference to Werner's table of 

 sequence would show what must needs be their relative posi- 

 tion. It was enforced, too, with such eloquence, that men 

 from all parts of Europe came to listen to the Freiberg teacher, 

 who had discovered a key to unlock the hitherto hidden his- 

 tory of the globe. Though Werner wrote almost nothing him- 

 self, yet his many illustrious pupils have fully expounded his 

 teaching.* 



The fundamental idea of the Wernerian doctrines was that 

 the visible portion of the earth's crust consists of successive 

 layers which were deposited universally, chiefly as chemical 

 precipitates from an original ocean that overspread the whole 

 globe. Werner assumed that there had always been inequali- 

 ties of the earth's surface, and that on the retirement of the 

 waters the first rock to emerge was the earliest that had 

 been thrown down from solution, viz., granite. In this way 

 he accounted for the position of this rock along mountain 

 crests. Next in succession came deposits of gneiss, mica- 

 schist, and clayjslate, with porphyry, quartz, and other crystal- 

 line masses. The highly inclined position of these strata, 

 which had been adduced by Hutton as irrefragible proofs of 

 disturbance and upheaval, were calmly regarded by the 

 Freiberg school as the original form in which the material 

 had been deposited, though the effect of subsidence in pro- 

 ducing disturbance of the masses was sometimes admitted. 

 In none of these higher and older rocks had any organic 



* The best expositions in English of the Wernerian geognosy are those of 

 Jameson, quoted in subsequent pages. 



