382 Geological Society. 



with it universal conviction, tlie theory which it implied, collected, 

 as it seemed at the time, from one or two obscure spots in Europe, 

 was for a while resisted and almost borne down by the opposite 

 doctrine of the aqueous origin of basalt ; which came from the school 

 of Freyberg, recommended by the power of a connected and com- 

 prehensive system, — a power in science so mighty for good and for 

 evil. Montlosier's Essay on the Volcanos of Auvergne, which ap- 

 peared first in 1788, was, however, not written with any direct 

 reference to this controversy, but was rather the exposition of the 

 clear and lively views of an acute and sagacious man, writing from 

 the fullness of a perfect acquaintance with the country which he 

 described, in which, indeed, his own estate and abode lay. In its 

 main scheme, although Desmarest's is mentioned with just praise*, 

 the object of this Essay is to criticise and correct a work of M, 

 Le Grand d'Aussy, entitled Voyage en Auvergne, But as the main 

 additions to sound theory which this work, contains, (a point which 

 here concerns us far more than its occasion and temporary effect) 

 we may, I think, note the mode in which he traces in detail the 

 effects which the more recent currents of lava (those which fol- 

 low the causes of the existing valleys) must have produced upon 

 the courses of rivers and the position of lakes ; and the idea, at that 

 time a very bold and, I believe, a novel one, that lofty insulated 

 ridges and pinnacles of basalt, which tower over the valleys, have 

 been cut into their present form by the long-continued action of 

 fluviatile waters, aided by a configuration of the surface very dif- 

 ferent from the present. The striking and vivid pictures which 

 Montlosier draws of such occurrences, are to the present day sin- 

 gularly instructing and convincing to those Avho look at that region 

 with the geologist's eye. After publishing this essay, M. Montlosier, 

 a man of varied and commanding talents, became involved in the po- 

 litical struggles of his time, and was an active member of the National 

 Assembly, to which he was sent as Deputy of the Noblesse of Au- 

 vergne. In his place there he resisted in vain the proposals for the 

 spoliation of the clergy ; and one speech of his on this subject was 

 very celebrated. After witnessing some of the changes which his 

 unhappy country had then to suffer, he became an exile, and resided 

 in London, where for some years he was the editor of the Courier 

 Franrais, a royalist journal. Under the empire, he returned to 

 France, and was employed in the Foreign Office of the Ministry, but 

 recovered little of his property except a portion of a mountain, which 

 was too ungrateful a soil to find another purchaser. The situation 

 however could not but be congenial to his geological feelings ; for 

 his habitation was in the extinct crater of the Puys de Vaches. 

 The traveller, in approaching the door of the philosopher of Ran- 

 dane, had to wade through scoriae and ashes ; and from the deep 

 basin in which his house stood, a torrent of lava, still rugged and 

 covered with cinders, has poured down the valley, and at the distance 



• After mentioning Guettard, he says, " Les memoires de M. Desmarest, 

 publics quelques annees apres, entrainerent tout-a-fait ropinion pub- 

 lique." (p. 20.) 



