X. On platina and native palladium from Brasil

Although platina has now been known to mineralogists for more than sixty years, yet it had not been discovered in any other places than Choco and Santa Fé, whence it was origi­nally brought, until about two years since M. Vauquelin discovered it in some gray silver ores from Guadalcanal in Estremadura. In analysing these ores, he found some frag­ments that contained as much as one tenth of their weight of platina, but he did not find it accompanied by any of the new metals that have lately been discovered in the Peruvian ore of platina. The specimen which I am now about to describe, is derived from a third source, and it is rendered the more interesting by having grains of native palladium mixed with it. This new mineral has lately been received from the gold mines in Brasil, by H. E. Chev. de Souza Coutinho, ambassador from the court of Portugal, resident in this country, and I am in hopes that some account of it may be acceptable to the Royal Society, although the analysis must necessarily be very im­perfect, from the small quantity to which my experiments have unavoidably been confined.