[ 6 7i } 
pretty tough compound ; which bore to be confider- 
ably flattened, cut with a chifiel, and bent almoft 
double before it cracked. Internally, it looked of a 
fine texture, and a very pale copper colour. 
4. A mixture of one ounce of platina and five of 
copper, firetched fomewliat more eafily under the 
hammer than the preceding ; and appeared of a 
redder colour. 
5. Upon increafing the copper to eight times the 
quantity of the platina, the compound proved fuffi- 
ciently tough, broke difficultly, and hammered well. 
It was much harder than copper, and of a paler co- 
lour. 
6. A mixture of one part of platina and twelve of 
copper was fomewhat more eafily extended under 
the hammer than the foregoing, and proved fofter to 
the file. It ftuck a little in the teeth of the file, which 
the compofitions with a larger proportion of platina 
did not. 
7. A mixture of one part of platina and twenty- 
five of copper was ftill a little paler coloured than 
pure copper, and confiderably harder and differ,, 
though very malleable. Upon increafing the copper 
a little farther, the mixture retained a degree of hard- 
nefs, and appeared of a fine rofe colour. 
8. Upon weighing the foregoing compofitions hy- 
droftatically, the diminution of gravity was found 
more regular than in the mixtures with other metals, 
being conftantly greater in proportion as the quantity 
of platina was larger* 
Platina 
