Memoir of M. D' Aubuisson de Voisins. 9 



This, in effect, was throwing a glove on the arena ; M. 

 D'Aubuisson thought that he could prove that the basaltic 

 masses, which crown some of the summits of the Erzgebii'ge,* 

 were nothing else than fragments of a grand continuous layer, 

 the modern deposit of waters, which had covered all the 

 country ; a conclusion which he seemed to consider as uni- 

 versal in regard to this kind of rock. Such also was Werner's 

 general opinion with respect to basalts : and the idea, however 

 paradoxical it may appear to us now, had then the support of 

 other authorities not less high in science ; thus, the woi-k in 

 question may be said to be only a development of this phrase 

 of Dolomieu, " The basalts of Saxony (black prismatic traps) 

 may be produced in the humid way." M. D'Aubuisson had 

 taken this as the epigraph of his memoir, and a touch- 

 ing allusion, made in the course of it, to the loss then so 

 recent and unfortunate, of the illustrious French geologist, 

 contributed to shed an interest over his work, and tended to 

 secure for the author the good-will of the Institute. Of this 

 an honourable proof was soon given him. He confessed in 

 his memoirs that he had hitherto enjoyed no opportunity of 

 observing any volcano, either in a state of activity or extinct. 

 The Academy gave him a commission to visit those of Au- 

 vergne and Vivarais, in order that he might obtain the ele- 

 ments of a discussion opposite to the former ; and he was 

 charged to make a detailed communication on the subject on 

 his return. 



M. D'Aubuisson worthily fulfilled this mission, for he ful- 

 filled it as a true friend of truth, affording a rare instance of 

 tlie rejection of the conviction he had entertained, and which 

 liad procured for him so many adherents. As soon as he 

 arrived in Auvergne, he observed the obvious passage of the 

 scoriaceous lavas into basalt, which are to be found there 

 at evei'y step. He could no longer doubt his error as to the 

 supposed Neptunian origin of the Saxony basalts, and, frankly 



with many imijortant annotations and additions. Dr Neill, like Dr Anderson 

 already mentioned, is one of the original members of the Worncrian SociGty. 



* The small chain which separates Saxony from Bohemia, and wliosc name 

 signifies metalli/crous mountains. M. Ue Bonnard made us acquainted with 

 their geological constitution, in 1816, in his important memoir, Esiai Qeoynos- 

 tique sur VJCrztjebirye. 



