[ 681 ] 
a faint yellowifh caft : It filed fofter, broke lefs readily 
from the chiflel, but cracked and fell in pieces under 
the hammer. 
3. One part of platina and four of brafs, covered 
as before with borax, and expofed to a quick fire, 
melted without lofs. This compound proved yel- 
lower than the preceding, filed fofter, bore to be cut 
fome depth with a chiflel before it broke, and re- 
ceived fome imprefiion from the hammer, firetching 
a little, but foon cracking in various directions. 
4. Upon increafing the brafs to fix times the 
weight of the platina, the compound appeared yel- 
lower, though fiill very pale. It proved fofter to 
the file - y and received a greater imprefiion from the 
hammer, and a deeper one from the chiflel, before 
it broke. 
f. A mixture of one part of platina and twelve of 
brafs was confiderably paler, and much harder, than 
brafs. It broke from the chiflel ; and cracked, be- 
fore it had extended much, under the hammer. It 
bore a good polifh, and was lefs apt to tarnifh than 
brafs though in both refpeCts it fell fhort of the 
compofitions with larger proportions of platina. 
2. With Copper and Tin. 
I. One hundred parts of platina, thirty-four of 
copper, and twelve of tin, covered with borax, be- 
came fluid in a ftrong fire, and fuffered no confider- 
able lofs. , The ingot proved extremely hard, fo as 
fcarce to be touched by the file ; and very brittle, 
breaking from a moderate blow, of a rough furface, 
and dull bell-metal colour. It bore a good polifh, 
and did not tarnifh in the air. 
4 R 
2. Platina 
