TWO ANTAGONIST DOCTRINES OF GEOLOGY. 5SS 



as well as of the same kind, with the volcanoes and earthquakes which 

 now shake the surface. His doctrine of uniformity was founded rather 

 on the supposed analogy of other lines of speculation, than on the 

 examination of the amount of changes now going on. "The Author 

 of nature," it was said, " has not permitted in His works any symptom 

 of infancy or of old age, or any sign by which we may estimate either 

 their future or their past duration :" and the example of the planetary 

 system was referred to in illustration of this. 4 And a general persua- 

 sion that the champions of this theory were not disposed to accept the 

 usual opinions on the subject of creation, was allowed, perhaps very 

 unjustly, to weigh strongly against them in the public opinion. 



While the rest of Europe had a decided bias towards the doctrine of 

 geological catastrophes, the phenomena of Italy, which, as we have 

 seen, had already tended to soften the rigor of that doctrine, in the 

 progress of speculation from Steno to Generelli, were destined to miti- 

 gate it still more, by converting to the belief of uniformity transalpine 

 geologists who had been bred up in the catastrophist creed. This 

 effect was, indeed, gradual. For a time the distinction of the recent 

 and the tertiary period was held to be marked and strong. Brocchi 

 asserted that a large portion of the Sub-Apennine fossil shells belonged 

 to a living species of the Mediterranean Sea : but the geologists of the 

 7-est of Europe turned an incredulous ear to this Italian tenet ; and the 

 persuasion of the distinction of the tertiary and the recent period was 

 deeply impressed on most geologists by the memorable labors of 

 Cuvier and Brongniart on the Paris basin. Still, as other tertiary 

 deposits were examined, it was found that they could by no means be 

 considered as contemporaneous, but that they formed a chain of posts, 

 advancing nearer and nearer to the recent period. Above the strata 

 of the basins of London and Paris, 6 lie the newer strata of Touraine, 

 of Bourdeaux, of the valley of the Bormida and the Superga near 

 Turin, and of the basin of Vienna, explored by M. Constant Prevost. 

 Newer and higher still than these, are found the Sub-Apennine forma- 

 tions of Northern Italy, and probably of the same period, the English 

 " crag " of Norfolk and Suffolk. And most of these marine formations 

 are associated with volcanic products and fresh-water deposits, so as to 

 imply apparently a long train of alternations of corresponding pro- 

 cesses. It may easily be supposed that, when the subject had assumed 

 this form, the boundary of the present and past condition of the earth 



4 Lyell, i. 4, p. 94. B Lyell, 1st ed. vol. iii. p. 61. 



