312 Scandinavian Diluvium. 



speaking of the great debacles, whose traces he discovered in the 

 Alps, has designated as the ruts caused by the passage of the 

 transported blocks, and on which the observations recently 

 made by M. Agassiz in the environs of Neufchatel have anew 

 contributed to fix attention.* 



A French philosopher, well known to the Academy, Count 

 Charles de Lasteyrie, an old travelling companion of Dolomieu, 

 whilst travelling himself in Sweden in the beginning of this 

 century observed similar furrows, and, some time afterwards, 

 one of the most illustrious geologists of the Scotch school, Sir 

 James Hall, observed analogous ones on the Corstorphine Hills, 

 two miles to the west of Edinburgh. Messrs Buckland and 

 Sedgwick have also discovered them in other parts of Great 

 Britain. M. Brongniart, during his travels in Sweden, verified, 

 along with M. Berzelius, the reality of these appearances. 



" We found," says he in the memoir already quoted,-!- '* our 

 celebrated and learned travelling companion, M. Berzelius, dis- 

 inclined to admit the constant occurrence of these furrows, un- 

 til, struck by their abundance and distinctness towards the de- 

 scent of Hogdal, he could not resist the evidence of so remark- 

 able a phenomenon. 



" Since then, this phenomenon has not ceased to be studied ; 

 the Academy has been able to judge of it by the letter already 

 quoted from M. Berzelius to M. Dumont d'Urville ; and I shall 

 now give, in addition, the following extract from a letter which 

 M. Berzelius did me the honour to address to me, the 8th No- 

 vember last, through M. Eugene Robert. 



" I send along with this letter, says M. Berzelius, a stone, 

 taken from the surface of the porphyritic mountains of Elfdalen 

 in Dalecarlia, which bears marks of a geological revolution, 

 whose traces my countryman M. Sefstroem has studied on our 

 mountains, and which appears to me to deserve the attention of 

 geologists. You are, without doubt, aw^re of a letter which I 



■ Letter from M. Agassiz to the Academy of Sciences. Comptes Bendus, 

 vol. 5. p. 506 (Meeting of 2(1 October 1837). Vide also Edin. New Phil. 

 Journal, vol. xxiv. for Agassiz's Memoir upon Glaciers, Moraines, and Er- 

 ratic Blocks. 



+ Ad. Brongniart's Notice sur les blocs de roches des ten-ains de trans- 

 port en Subde {Annales d^s Sciences Naturelles, vol. 14, p. 17). 



