S24 Intelligence and Miscellaneous Articles. 



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in his laboratory ; he was certain of the results which he obtained, 

 but he says that he met with difficulties which required a hand more 

 practised in manipulating than his to overcome. Some specimens 

 yielded an ascertainable quantity, but these were the exceptions ; at 

 other times very clear indications of platina were obtained, but the 

 quantity was not determinable. Of one hundred specimens more 

 than eighty yielded none. 



Being of opinion that the platina of Chapeau was not a solitary 

 deposit of platina in the Alps, the author directed his researches to 

 Saint- Arcy near the Mure (Isere), and in the bournonites, dolomites, 

 and altered limestones of these mountains, he found platina. These 

 bournonites were treated in the same way as the gray copper of the 

 Chapeau, and similar results were obtained. Platina was sometimes 

 found in 5 grammes of the mineral, while in other cases none could 

 be discovered in 20 grammes ; the metal is however more common 

 at Saint- Arcy than at the Chapeau. A third locality is the Plan des 

 Cavales on the Montagne des Rousses, in Oisans (Isere). These 

 mountains are composed of protogenes, gneiss, talcose schists, lime- 

 stones and dolomite. 



At the Plan des Cavales there are many ancient workings anterior 

 to the discovery of gunpowder. Among the rubbish there occur 

 specimens of carbonate of copper of a foliated striicture, containing 

 as much as 50 per cent, of copper, and this carbonate, which is of a 

 dirty green colour, yielded in two cases ascertainable quantities of 

 platina ; other examinations did not yield a trace, but the author 

 states that he possessed but a small quantity of the mineral. 

 Lastly, on the right bank of the Bens in Savoy, on the lands of 

 Presles, there was found a fourth locality, on which gray and car- 

 bonate of copper, containing but little silver, gave traces of platina ; 

 it occurred in all the specimens, and in some of them its quantity 

 was ascertainable, though with difficulty. 



At the request of M. Gueymard, M. Ebelmen examined the spe- 

 cimens from these four localities, and he found platina in several of 

 them, though in quantity too small for working. M. Vicat, jun., 

 also found indications of the presence of rhodium, and the same ob- 

 servation was made by the author. — Comptes Rendus, 31 Decembre, 

 1849. 



ANALYSIS OF TIN FROM THE MINES OF BANCA. 

 BY M. MULDEIl. 



This metal was found to consist of — 



Tin 99-961 



Iron 0019 



Lead 0014 



Copper 0006 



100-00 

 It contains therefore only j— of foreign metals. It resulted from 

 the examinations performed, that peroxide of tin consists of — 



