Process of procuring pure Platinum, &e. 171 
the act of inhaling the gas, it would pass from the bladder into 
his lungs, and when he exhaled, the breath would pass through 
the other tube that has the valve to open outward into the air. 
I remain respectfully, &c. 
Pratten’s Row, Lawrence Hill, Bristol, Jonn Moore, Jun. 
Jan. 10, 1822. 
XXXIX. Process for procuring pure Platinum, Palladium, 
Rhodium, Iridium, and Osmium, from the Ores of Platinum. 
By M. Baruet, Chemical Operator in the School of Medi- 
cine at Paris *. 
Lk. 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 iron ¢ than the preceding ; both ores exist 
always in the form of small spangles, which vary in size 5 plati- 
num ore is one of the most compound known: besides the five 
metals above noted, several others are found in it, especially two 
kinds of ferruginous sand, one of them attractible by the magnet, 
the other not, and which is a combination of the oxides of tita- 
nium 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 complexity 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, palladium, rhodium, iridium, and osmium, 
from each other, and the rest of the bodies, the following method 
is the one which long experiei:ce has proved most successful. 
2. The ore is triturated in a cast-iron mortar for a considera- 
ble time, during which a stream of water is constantly passed 
over it, to wash away the ferriferous sand, the titanite, and chro- 
mate of iron, reduced to an impalpable powder. When the ore 
is very brilliant, it is left to settle for an instant ; the water is de- 
canted off, and it is then exposed in a crucible to a red heat during 
a quarter of an hour. The whole mercury is thus volatilized, 
when we can readily distinguish the spangles of alloy of gold and 
copper by their colours. 
3. The calcined ore being introduced into a tubulated retort, 
we pour over it half its weight of nitro-muriatic acid (aqua regia) 
* From Mr. Brande’s Journal of Science. This valuable memoir derives 
eculiar interest from the large importation of the above ore daily expected 
rom South America, in consequence of the negotiation between M. Zea 
and some London merchants. d 
+ Rather, the fine black powder, or ore of iridium and osmium, noticed 
in paragraph 38.—Tr. 
¥.2 composed 
