C 667 ] 
peared of a leafy, and thofe with a fmaller, of a fine 
fibrous texture, which feeraed in general to be cha- 
raderiftics of the perfed union of the platina and 
lead. They all looked whiter and brighter than at 
at firfi, but tarnifhed fooner in the air. One mixture 
in particular, of four ounces of platina and twelve of 
lead, broke into large, white, bright, ihining, talc- 
like flakes j which, on expofure to the air, changed 
in- a little time to a reddifh, a purple, and a deep 
blue ; and at length turned flowly to a dark blackifli 
colour. 
10. On examining thefe compounds hydroflati- 
cally, their gravities turned out lefs than they ought 
to have been according to their calculation, but not 
fo much lefs as thofe of the compofitions of platina 
and tin. 
Platina 
Platina 1, Lead 1 
Platina 1, Lead 2 
Platina 1, Lead 4 
Platina 1, Lead 8 
Platina 1, Lead 12 
Platina 1, Lead 24 
Lead 
Specific Gravity. 
By Experiment. 
I/. OOO 
By Calculation. 
Difference. 
14 . 
029 
14 . 
I93 
0 . 
164 
12. 
9 2 5 
2 f 7 
O. 
33 2 
12. 
404 
12. 
509 
0. 
105 
II. 
94-7 
I 2. 
OO9 
0. 
062 
II. 
77 + 
II. 
8l8 
0. 
044- 
II. 
I I. 
575 
386 
I I. 
6lO 
0. 
° 3 ? 
Remark. It appears, that a fmall proportion of 
platina is taken up and kept fufpended by lead, in 
a very gentle heat; but that a large proportion is not 
taken up near fo eafily as by tin, and if united by 
a ftrong fire, fubfides in part upon its abatement. A 
little quantity ftiffens and hardens lead more than it 
4 P 2 does 
