138 "Dr. "Berg-er 0/1 the physical Structure 



It is easier to shew, that these characters are for the most part 

 erroneous, than to substitute others more precise, and consequently- 

 better, in their stead : a negative truth is however in my opinion 

 always of some value. 



Monte Rosa is we know, next to Mont Blanc, the highest moun- 

 tain in Europe ; there being a difference of only ninety-six feet 

 between them. All mineralogists and geologists agree that it is an 

 assemblage of primitive mountains.* Brochant does not state the 

 extent of that vast deposit of newer serpentine which he tells us 

 exists at Zoeblitz in Saxony ; I think however, that a circuit of 

 mountains of serpentine, the internal diameter of which is thirty 

 thousand feet, and which is bounded by walls, if I may so express 

 myself, fourteen thousand five hundred and eighty feet high, cannot 

 be considered as a deposit of very limited extent. f 



As a cap of eternal snow completely covers the upper part of the 

 mountain, it is only by analogy we can say that the serpentine reaches 

 to the top, it can however be traced to a very considerable height. 

 I have observed it myself at ten thousand four hundred and sixteen 

 feet above the level of the sea, at the fort of St. Theodule, in the 

 passage of Mont Cervin. This may serve as a reply to the assertion 

 of Brongniart, that the serpentine of oldest formation does not rise 

 very high. He does not omit, it is true, to mention Monte Rosa as 

 an. exception, but he has forgot to produce a single example in sup- 

 port of his opinion. The potstone which is found at Alagna at the 

 foot of Monte Rosa, at the height of three thousand eight hundred 

 feet above the level of the sea, may be considered, I think, by all 



* Saussure compares the assemblage of mountains which form Monte Rosa to a tennis 

 court. 



+ Voyage dans les Alpes, ^ 2140, 



