42 
’Examination of a Metallic Button , Qc. 
[Feb. 
riments, however, I am aware of the difficulty of separating lead from platina, by 
heat : for an alloy of 8,0 gold, and 2,0 platina, cupelled with 50,0 lead, retained 1,0 
of the latter, without diminution, under the most violent forge heat. The same, 
in a degree, may be the case with arsenic, and the fusibility of the bead is certainly 
strongly corroborative of its presence. 
Examination of B. 
”• Iong flat «7stal s separated from solution being dissolved in water, and 
set aside produced a deposition of a number of minute, rose coloured crystals of 
irregular form, with waxy lustre. They were readily fusible much below a 'red heat 
spreading on talc, or on borax, ana leaving a black, insoluble atom, without im- 
parting a colour to the flux. The quantity was two small to allow a further exarni- 
nation. It is possible, from their colour, that they may be a salt of rhodium 
The a,„ oi^ rlutionjon evaporation to dryness, left a number of silveiTfibrous 
ci ystals, which bore the appearance, and exhibited fh P nmno y norous 
probably mixed with that of platina. ° f ’ mUriate ° f 
o. Proper means were not taken to separate rhodium i,., 
sent,) from the insoluble grains at the proper sta-e of the l 1 ^ ^ be a " y Pre ' 
melius has pointed out an elegant process for this purpose JLl’T't Ber ' 
pected substance infused super-sulphate of potash which y ’ ° d, ° cst lhe »M- 
and leaves the oxyde of iridium untouched. ’ h d,ssol '' es t,le rhodium, 
I submitted the black insoluble residue D Cnf tr> • 
isr,-* C irrir's: 
ascertained the presence of the others In so ro r ! ' most Probably have 
dance can be placed upon the proportions of . pllCated a sub stance, little depen- 
an assay of 10 grains. I think, however the folio P mgredients furnished by 
composition, in round numbers ’ n,a f be fairly set down as its 
Platina, 
Gold, 
25 
Iridium, 
5 
Osmium, J 
40 
Iron, 
Arsenic, t 
10 
Lead, j 
Rhodium ? 
20 
Palladium ? 
100 
The metal is undoubtedly, therefore n 
^r. Lane on being the first to discover tl ° y ° fplatina * and we may congratulate 
fuse th “ SpeC,men of the grains of metaf w° ’ rOUgh that gentleman's 
always “ ‘ arger fluuut'ty than the ’ present Sh ° uld be made t0 
.wvn :;i a a c :?Ctie, Z y lt:: 
