482 



THE GEOLOGIST. 



Many other antiquaries follow the old and exploded notion of these so-called 

 diluviai gravels having been solely formed by the action of water. This is an 

 error, for water has been only the 'motive power in their distribution. Beyond 

 this, all it has effected has been by its continued frictional action in the partial 

 rounding by abrasion of the sharp angidar edges of those more or less triangular 

 frao-ments into which flints naturally break by the action of frost or by per- 

 cussion. Whole beds of shattered flints are of frequent occurrence in chalk, 

 and the mere waste and destruction of the strata would liberate heaps of frag- 

 ments with angular edges as sharp as those of a flint freshly broken by the 

 hammer. The knocking action of one pebble dashed against another could not 

 produce the triangular pieces we have alluded to, but would cover the sur- 

 face with innumerable pits, due to the natural conchoidal fracture of the cliips 

 broken out. 



M. de Perthes next details the researches made by himself. Dr. Eigolet, and 

 others in the neighbourhoods of Abbeville and Amiens, some accounts of which 

 were, from time to time, laid before the " Societe d'Emulation" of Abbeville, 

 and " Societe des Antiquahes de Picardie," and published in their respective 

 transactions. 



(To be continued.) 



BRITISH ASSOCIATION MEETING. 



( Continued from page 444^. 



QuEniES ON Slickensides submitted to the President of the Geolo- 

 gical Section, Aberdeen Meeting, September, 1859, by Mr. J.' Price, of 

 Birkenhead, with Beplies to the Queries by Professor D. T, Ansted. 



I offered the following remarks to the Section, under a conviction that 

 individual and local observation of small facts could never, as such, be 

 out of place at the meetings of an association so eminently Baconian 

 as that then assembled at Aberdeen ; and that this must ever be the 

 province of the majority of naturalists — to provide instances for the few master 

 minds to generalize. I mean to include under the name " Slickensides" every 

 mineral surface which, apart from crystallization, exhibits an extraordinary 

 degree of polish. And as I believe tliis phenomenon has never yet received 

 anything approaching to a satisfactory explanation, I wish to call the attention 

 of practical geologists to the subject, and induce them to look out for it in sec- 

 tions (whether natural or artificial) of every rock-formation. I am acquainted 

 with tlie fact in situ only in the neighboui'hood of Birkenhead (New Red), par- 

 ticularly the celebrated Labyrinthodon quarries at Storeton, where it is very 

 well illustrated, and in the "mountain-limestone" at Llysfaen and Eryn 

 EurAiTi, near Abergele, North Wales. But I believe I have met with hand 

 specimens of it (generally ballast) in granite, serpentine, coal, coal-shale, and 

 trap, near Shrewsbury. I presume "specular" galena, antimony, &c., to be the 



