462 Geological Society. 



The spirited publications of Mr. Scrope, especially his plates 

 in illustration of the volcanic district of Central France, have 

 renewed the attention of geologists in England to that country, 

 from whence so many luminous views may be obtained on various 

 points of theory. By placing the phaenomena before the eye, Mr. 

 Scrope has enabled his readers more easily to appreciate the merit 

 of M. De Montlosier's admirable Essay on the Extinct Volcanoes 

 of Auvergne*; a work published more than thirty years ago, and 

 containing most correct inductions and forcible reasoning on the 

 origin of valleys, but almost unknown amongst us, till its doctrines 

 were brought under our attention in a recent paper of Messrs. Lyell 

 and Murchison f , which confirms M. De Montlosier's views by 

 new and interesting details. We are enabled, by this various as- 

 sistance, to enter into the evidence derived from Auvergne, in 

 support of the opinion which ascribes the origin of valleys, in 

 many cases, to the gradual but long continued action of the streams 

 of which they are now the channels: — a theory in fact brought 

 forward several years before by De Saussure ; to whose priority 

 M. De Montlosier, — when conducted by other evidence, to views 

 precisely the same, — has very candidly given his testimony J. 



1 select these names from many of eminence, which might be 

 mentioned, in connexion with this doctrine, and with the geology 

 of Central France, because it is to De Saussure and De Montlosier 

 that we owe the principle, — and to the beautiful drawings of Mr. 

 Scrope, decidedly the best graphic illustration of that interesting 

 tract. And I avail myself of this occasion to add, that De Mont- 

 losier's work affords a good example of the injury arising from our 

 being too generally unacquainted with the publications of the con- 

 tinent. A few years, it is true, have materially changed the cha- 

 racter of books upon Geology; but there is much in the topographi- 

 cal description of almost every country, which none of us ought to 

 neglect. With the recent productions of France we are in general 

 familiar ; but we know much less than we ought to do, even of the 



* " Essai sur la Theorie des Volcans d'Auvergne :" Riom et Clermont j 

 1802. — Anonymous. 



f This paper will be published in the ensuing Number of Professor 

 Jameson's Edinburgh Philosophical Journal. 



J " Essai, &c. Chap. VI. " Des Revolutions oper^es par les eaux fluvia- 

 tiles." The volume of De Saussure, referred to by M. De Montlosier, bears 

 the date of 1786 ; the passages are in § 920 ; vol. i- 4to. 



As M. De Montlosier's work of 1802 is stated to be only a reprint of 

 the same publication in 1788, (Cuvier's eloge of Desmarest; — Eloges, II. 

 p. 362,) it is the more remarkable that Mr. Playfair (whose illustrations of 

 the Huttonian theory were first published in 1802,) does not appear to have 

 been acquainted with it ; since it cannot be doubted that he would have 

 availed himself of such evidence, as that adduced by De Montlosier, from a 

 series of phaenomena entirely distinct from those to which he himself 

 refers, in his sections on the proposition that " rivers have hollowed out 

 their valleys ;" which are composed with admirable force and eloquence. (Il- 

 lustrations, §§ 316—329.) This coincidence, in the views of two such 

 writers, without communication, is strongly in favour of their correctness. 



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