96 Biographical Sketch of Alexander Brongniart. 



siasm, as judicious as fruitful, for the vast field which he had 

 so sagaciously entered, he became in a few years, the legis- 

 lator in this branch of geology, then so new and important. 

 He settled the laws of it, by examples which, in such a case, 

 are the most solid of all precepts. Like that Greek philoso- 

 pher, in whose presence motion was denied, M. Brongniart 

 advanced in tliis career with an intelligent and indefatigable 

 ardour, and every one of his steps has been an important 

 discovery. A conqueror in a new field, M. Brongniart set out 

 in 1817 for Switzerland, tiie Alps, and Italy, accompanied by 

 his son, and one of his most skilful pupils, M. Bertrand Geslin. 

 In these countries, where Saussure had already immortal- 

 ized himself, he fixed, in the most unexpected manner, land- 

 marks which are still standing, and which no longer give 

 place but to discussions in detail, without which no work on 

 natural history can be perfect. "Who has not been struck 

 with the boldness, as fortunate as it was surprising, with 

 which M, Brongniart associated the black limestones of the 

 mountain of Fis, in Saxony, with our chalk formations of the 

 north of France ! In 1822, all the results of this kind which 

 he had obtained, were inserted in a second edition of the Geo- 

 logical Description of the Neighbourhood of Paris, which thus 

 became more especially the monument of his genius. 



But he did not limit himself to the modern foi'mations, the 

 particular object of this great work. Later, in 1824, M. 

 , Brongniart visited Norway and Sweden with the same view. 

 He was warmly received by M. Berzelius, who wished to act 

 as his guide and interpreter in a country whose language 

 was unknown to him. He there laid down the first founda- 

 tions of a classification of the most ancient fossiliferous for- 

 mations. It was likewise in this voyage to Scandinavia, 

 that he united the elements of a memoir on erratic blocks, 

 which happily associated his name with those of the Saus- 

 sures and De Buches, in the study of a phenomenon on which 

 the extent of the revolutions of the globe are inscribed in 

 the most striking characters. 



I ought also to speak to you of his remarkably original 

 memoir on the Ophiolithes of the Apennines, his clear and 

 ingenious vicAVS on volcanoes, and Vesuvius in particular. 



