MODE XIV. CALCAREOUS GLUTENITE. 



described by Saussure, may suffice. He observed 

 it at the Col de la Seigne, near the mountain 

 of Bonhomme. 



" On this road we find a quantity of fragments sfliguia 

 of a very singular calcareous bricia ; and conti- 

 nuing to ascend, we leave on the right, above the 

 path, the rocks from which these fragments are 

 detached. The same bricias are again found in 

 the same situation, on the opposite slope of the 

 Col de la Seigne, and in the White Alley : but I 

 shall describe them here, that I may not return to 

 them. The paste of these bricias is sometimes 

 white, sometimes grey ; and the fragments which 

 it contains, are some white, some grey, others 

 brownish red, and almost always of a different 

 colour from the paste which unites them. They 

 are all of a calcareous nature, at least such were 

 all those that I could see ; and it is remarkable 

 that they have all a lenticular form very much 

 flattened, and that they are all placed in the 

 direction of the plates of the rock : one would 

 say, on seeing them, that they had all been com- 

 pressed and bruised in the same direction. This 

 same stone is mixed with mica, especially in the 

 interstices of the layers, and between the frag- 

 ments and the paste which unites them ; but no 

 mica is observed in the fragments themselves. 



