246 M. Baruol on the Process 



Art. VI. Process for procuring pure Platinum, Palladi- 

 um, Rhodium, Iridium, and Osmium, from the Ores of 

 Platinum. By M. Barvf.1,, Chemical Operator in the 

 School of Medicine at Paris. 



Communicated by the Author*. — With Supplementary IJemarks by the 



Translator. 



1. Two sorts of platinum ore occur in commerce, one of 

 which is white and brilliant, the other is blackish coloured. 

 The latter contains much more ironf than the preceding; both 

 ores exist always in the form of small spangles, which vary in 

 size ; platinum ore is one of the most compound known ; be- 

 sides the five metals above noted, several others are found in il, 

 especially two kinds of ferruginous sand, one of them attrac- 

 tible by the magnet, the other not, and which is a combination 

 of the oxides of titanium and iron ; there is besides chromate 

 of iron, some copper, particles of gold alloyed with silver, with 

 copper, and mercury. It contains, moreover, some sulphuret of 

 lead and copper. We may hence judge of the singular com- 

 plexity of this mineral, and be ready to acknowledge that its 

 exact analysis, in regard to the proportion of its constituents, is 

 nearly impossible. In order to separate the platinum," palla- 

 dium, rhodium, iridium, and osmium, from each other, and the 

 rest of the bodies, the following method is the one which long 

 experience has proved most successful. 



2. The ore is triturated in a cast-iron mortar for a consider- 

 able time, during which a stream of water is constantly passed 

 over it, to wash away the ferriferous sand, the titanite, and 

 chromate of iron, reduced to an impalpable powder. When 

 the ore is very brilliant it is left to settle for an instant ; the 



* This valuable memoir derives peculiar interest from the large impor- 

 tation of the above ore, Jaily expected from South America, in consequence 

 of the negociation between M. Zea and some London merchants. 



t Rather the fine black powder, or ore of iridium and osmium, noticed 

 in paragraph H.— Tr. 



