[ 6 72 ] 
Platina 
Platina i, Copper i 
Platina i, Copper 2 
Platina 1, Copper 4 
Platina 1, Copper j 
Platina 1, Copper 8 
Platina 1, Copper 12 
Platina i, Copper 25 
Copper 
Remark. In the foregoing fufions, though in ge-> 
neral no flux was made ufe of, there was fcarce any 
fenfible lofs of weight, unlefs in N° 1, where the 
large proportion of platina required the fire to be 
railed to a violent degree. This feems owing, in 
good meafure, to the platina preventing the fcorifi- 
cation of the copper : For upon melting pure cop- 
per a great number of times, both with and with- 
out fluxes, there was conftantly a little lofs. 
A fmall proportion of platina appears to improve 
the hardnefs of copper, without injuring its colour, 
or, fo far as could be judged, its malleability. The 
mixtures with a large proportion of platina are dif- 
ficultly extended under the hammer when cold; and 
whilft red hot, fly in pieces. They all bear a good 
polilh, and do not tarnifh in the air fo much, or fo 
loon, as pure copper. 
Article 6. 
Platina with Iron. 
Iron, the laft of the metals in point of fufibility, 
was ieveral times attempted to be united with platina, 
in 
Specific Gravity. 
By Experiment. 
I 7 . OOO 
By Calculation. 
Difference. 
II. 400 
12. 915 
1. yiy 
10. 410 
n- 573 
1. 143 
9. 908 
10. 464 
o. 556 
9. 69 3 
10. 191 
0. 498 
9. 300 
9 • 73 S 
0. 438 
9. 2 fl 
9. 45-8 
0. 207 
8. 97 0 
8. 830 
9. 144 
0. 174 
