found in crude Platina. 425 
blowpipe, yet it seems to be more in the state of an amalgam 
than in complete fusion. 
(E 6 .) When 6 parts of gold are alloyed with 1 of rhodium, 
the compound may be perfectly fused, but requires far more 
heat than fine gold. There is no circumstance in which rhodium 
differs more from platina, than in the colour of this alloy, which 
might be taken for fine gold, by any one w r ho is not very much 
accustomed to discriminate the different qualities of gold. On 
the contrary, the colour of an alloy containing the same pro- 
portion of platina, differs but little from that of platina. This was 
originally observed by Dr. Lewis. “ The colour was still so 
“ dull and pale, that the compound (5 to 1) could scarcely be 
“judged by the eye to contain any gold.”* 
I find that palladium resembles platina, in this property of 
destroying the colour of a large quantity of gold. When 1 part 
of palladium is united to 6 of gold, the alloy is nearly white. 
(E 7.) When I endeavoured to dissolve an alloy of silver or 
of gold with rhodium, the rhodium remained untouched by either 
nitric or nitro-muriatic acids ; and, when rhodium had been fused 
with arsenic or with sulphur, or when merely heated by itself, it 
was reduced to the same state of insolubility. But, when 1 part 
of rhodium had been fused with 3 parts of bismuth, of copper, or 
of lead, each of these alloys could be dissolved completely, in a 
mixture of 2 parts, by measure, of muriatic acid, with 1 of nitric. 
With the two former metals, the proportion of the acids to each 
other seemed not to be of so much consequence as with lead ; 
but the lead appeared on another account preferable, as it was 
most easily separated, when reduced to an insoluble muriate by 
evaporation. The muriate of rhodium had then the same colour 
* Lewis’s Philosophical Commerce of Arts, p. 526. 
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