^26 Sctenlific News, Actounii of Books, isfc, 



laftly, that the liquor when cold throws down, by means of the acids, the golden tartar, 

 and not kermes, becaufe the brown oxide becomes more oxided by the oxygen of the 

 water and pafles to the ftate of the orange coloured oxide. 



In the third paragraph Cit. Thcnard makes a recapitulation of his experiments. 



Bulletin des Sciences, An. 8. No. 31, 



On the StruEiure of the upper Pyreneans, by Cit. RaymoiTD. Communicated to the National 



Injlitute of France. 



Pallas in Afia, Sauflure, Deluc, and Dolomieu in Europe, have obferved, that in large 

 chains of mountains, there is ufually in the center a more elevated chain of granite, ac- 

 companied on each fide by a collateral fchiftus chain, and Hill lower by another, which is 

 calcareous. 



The Pyreneans appear to accord with this law. Their higheft points are certainly cal- 

 careous, and this circumftance has embarrafled obfervers. 



Cit. Raymond has afcertained, that the refpeftive difpofition of the five orders of moun- 

 tains, exifts no lefs in thefe than in the other chains, but with this difference, that the cal- 

 careous chain on the Spanilh fide is the moft elevated of the five, and that in returning on 

 the fide towards France the fouthern fchiftus chain is found, then the granite, or middle, 

 and the northern fchiftus and calcareous chains, gradually diminifliing in height, which is 

 the caufe why the geological axis of the Pyrenees, or the granite, is not the fame as the 

 geographical axis, or that which determines the courfe of the waters. , 



In order to demonftrate the accuracy of his obfervations he has drawn on the chart five 

 lines, correfponding with the five orders of the mountains, each of which is found to pafs 

 through the fummits or mafles of the fubftance, which forms the charafter of that order 

 which the line indicates. 



The granitic axis pafles through the fummits of Neouvielle, Pic long, Bergons, and 

 Monne, the fchiftofe chain, and the northern Gneifs, through the Pic du Midi,, and the 

 fouthern through thofe of Troumoufe, Pic mene, Vignemale, and. the Pic du Midi 

 de Pau. 



The calcareous ridges on the fide of France are thofe of Gampan and of SarrancoHn, fo 

 much celebrated for the marble they produce, and thofe on the fide of Spain form Mont 

 Perdu, Marbore, and le Pic blanc, which are among the moft elevated fummits of thefe 

 inountains.^ 



Abridged in the Bnlktin de la Sec. Philom. No. 41, An. S. 



letter 



