[ 66 + 3 
near four times its weight : That with larger propor- 
tions it forms compounds tolerably dudtile, but ren- 
ders the texture of the tin coarfer, and debafes its 
colour. The difference in colour of thefe compo- 
fitiens was much lefs confpicuous on the touchftone, 
than when the fradtures of the ingots were examin- 
ed ; though, on clofe infpedtion, they appeared all 
fenfibly duller and darker than pure tin, and the 
more fo, in proportion as the platina prevailed. They 
all tarnifhed in the air ; thofe leafl, which had a very 
ffinall or a very large proportion of platina. 
It is remarkable, that though tin is a metal very 
readily deftrudtible by fire, yet in mofl of the pre- 
ceding fufions, there was fcarce any fenfible lofs of 
weight. This is to be attributed not folely to the 
admixture of the platina, but likewife to the flux 
made ufe of, and more particularly to the celerity 
and fhort continuance of the heat. In N° 2 and 7, 
the only ones, in which the lofs was at all confiderable, 
the fire was flowly railed, and long contiaued. 
Article 2. 
Platina with Lead. 
1. Equal parts of platina and lead were injected 
into a mixture of black flux and common fait, pre- 
vioufly melted together j and the fire haflily raifed 
by bellows. A much ffronger heat was requilite 
than for the fufion of platina with an equal quantity 
of tin ; and the lofs was confiderably greater, amount- 
ing to about one-flxty-fourth. The metal yielded 
difficultly to the file ; broke, from a moderate blow, 
of a clofe texture, uneven furface, and rough jagged 
edges : 
I 
