[ 66 3 ] 
colour was whiter, and the grain finer and evener, 
than thofe of the preceding compofitions 5 though in 
both refpedts it fell confiderably fhort of pure tin. 
7. Several of thefe compofitions, covered with 
black flux, which had been previoufly melted, were 
expofed, in crucibles clofely luted, to a flrong fire in 
a wind furnace, which was fteadily kept up for eight 
hours. When taken out, they were all found to have 
fuffered fome diminution, amounting to about one- 
fortieth of the tin. In appearance and quality, there 
was no fenfible alteration, except that the mixture 
feemed more uniform, and the grain a little finer. 
8. The remarkable gravity of platina induced us 
to examine the feveral mixtures hydroftatically. Here 
it was found, that the fpecific weight of the com- 
pound conftantly turned out lefs than the medium of 
the gravities of the two ingredients ; and generally 
the more fo, as the proportion of the platina was the 
greater. 
Specific Gravity. 
Platina — 
By Experiment. 
17 . OOO 
By Calculation. 
Difference. 
Platina 1, 
Tin 
1 
IO. 
827 
I 2. 
opo 
I. 
263 
Platina 1, 
Tin 
2 
8. 
971 
IO. 
473 
r. 
481 
Platina 1, 
Tin 
4 
7 - 
794 
9 - 
144 
1. 
35 ° 
Platina 1, 
Tin 
8 
7. 
7°7 
8. 
271 
0. 
y66 
Platina 1, 
Tin 
12 
7 * 
613 
7 - 
937 
0. 
322 
Platina 1, 
Tin 
24 
7 - 
47 1 
7 - 
573 
0. 
102 
Tin 
7 - 
180 
Remarks . It appears from the foregoing experi- 
ments, that platina melts with at leaf!; equal its 
weight of tin : That it defiroys the malleability of 
near 
