NATIVE PLATINUM FROM BRITISH COLUMBIA. 21 



Non-magiutic Magnetic. 



Platinum 68-19 78-43 



Palladium 0-26 0-09 



Rhodium 3-10 1-70 



Iridium 1-21 1-04 



Osmium »... 



Copper 309 3-89 



Iron 7-87 9-78 



Osmiridium 14-62 3-77 



Gangue (imbedded chromite) 195 1-27 



100-29 99-97 



Specific gravity 17-017 16-095 



from which it will be seen, that the magnetic portion contained much less palladium 

 and rhodium, and very considerably less included osmiridium, but contained somewhat 

 more copper, nearly two per cent, more iron, and a little over ten per cent, more platinum, 

 than the non-magnetic portion. On comparing the composition of the sub-portion a — 

 which was not in the slightest degree magnetic, — with that of sub-portion e — which 

 was magneti-polar — it will be observed that the difference in the percentage of iron is 

 not very great, the latter containing barely half a per cent, more than the former. From 

 this it might be inferred that the magnetic property of Portion II was not altogether, if 

 indeed at all, dependent upon the amount of iron which it contained. 



The weights of the material constituting sub-portions a, b, c, d and e, having been 

 added together, as likewise the amounts of each of the several constitutents found in these 

 sub-portions — calculation sliowed the composition of this ore, after careful separation of 

 the associated grains of foreign matter, taken as a whole, as determined upon the 1'7'894 

 grams material, to be as follows : — 



Platinum 7207 



Palladium 0-19 



Rhodium 257 



Iridium 1-14 



Osmium 



Copper 3-39 



Iron 8-59 



Osmiridium 10-51 



Gangue (imbedded chromite) 1'69 



100-15 



Specific gravity 16656 



In common with the native platinum of Oregon and Australia, this ore contains a 

 large proportion of osmiridium, but differs from the material of those localities in that 

 it contains a higher percentage of copper and iron, in which regard it more nearly 

 approaches in composition to some Russian specimens of this mineral. 



The following analyses of platinum ores, by Deville and Debray, are given for com- 



