NOME I. MIAGITE, 



67 



ness of the black and while which compose 

 them. Besides, these stones are harder than 

 marble, and capable of the most lively polish. 



" The bases of the mountains, which enclose 

 the glacier of the Miage on the right and on the 

 left, are all composed of rocks of this kind. As 

 to their exterior form, they appear almost every 

 where as assemblages of pyramidal large plates 

 very pointed ; five, six, or even a greater num- 

 ber of these plates often leaning against each 

 other, though separated by fissures which de- 

 scend to the bottom. The pyramids are them- 

 selves divided by slits parallel to their sides, and 

 which often meet in such a manner as to indi- 

 cate partial pyramids, similar to those of which 

 they form a part. In some, there are seen slits 

 perpendicular to the planes of the plates; and 

 which cut in the same direction many consecu- 

 tive plates. The blocks, which are detached 

 from the faces of these pyramids, leave empty 

 spaces of a square form, particularly in the 

 upper part, because the lower must necessarily 

 slip, before the upper blocks can disengage 

 themselves. 



" I asked myself, in observing all the pheno- 

 mena, if the whole of this organisation did not 

 prove a crystallisation, which had produced, at 



