SYSTEMATIC DESCRIPTIVE GEOLOGY. 51 5 



bably, of the labors of Strachey in England. He divided mountains 

 into three classes ;' primitive, which were formed with the world ; 

 those which resulted from a partial destruction of the primitive rocks 

 and a third class resulting from local or universal deluges. In 

 1759, also, Arduine, 9 in his Memoirs on the mountains of Padua, 

 Vicenza, and Verona, deduced, from original observations, the dis- 

 tinction of rocks into primary, secondary, and tertiary. 



The relations of position and fossils were, from this period, in- 

 separably connected with opinions concerning succession in time. 

 Odoardi remarked, 10 that the strata of the Sabapennine hills are 

 unconformable to those of the Apennine, (as Strachey had observed, 

 that the strata above the coal were unconformable to the coal ; n ) and 

 his work contained a clear argument respecting the different ages of 

 these two classes of hills. Fuchsel was, in 1762, aware of the distinct 

 ness of strata of different ages in Germany. Pallas and Saussure were 

 guided by general views of the same kind in observing the countries 

 which they visited : but, perhaps, the general circulation of such 

 notions was most due to Werner. 



Sect. 2. Systematic form given to Uetcripiive Geology.- Werner. 



WERNER expressed the general relations of the strata of the earth by 

 means of classifications which, so far as general applicability is con- 

 cerned, are extremely imperfect and arbitrary ; he promulgated a 

 theory which almost entirely neglected all the facts previously dis- 

 covered respecting the grouping of fossils, which was founded upon 

 observations made in a very limited district of Germany, and which 

 was contradicted even by the facts of this district. Yet the acuteness 

 of his discrimination in the subjects which he studied, the generality 

 of the tenets he asserted, and the charm which he threw about his 

 speculations, gave to Geology, or, as he termed it, Geognosy, a popu- 

 larity and reputation which it had never before possessed. His 

 system had asserted certain universal formations, which followed each 

 other in a constant order ; granite the lowest, then mica-slate and 

 clay-slate ; upon these primitive rocks, generally highly inclined, rest 

 other transition strata ; upon these, lie secondary ones, which being, 

 more nearly horizontal, are called flotz or flat. The term formation, 



8 Lyell, L 70. 9 Ib. 72. 



10 Ib. 74. n Fitton, p. 157. 



VOL. II 33. * 



