638 
MR. EDWARD MATTHEY ON THE LIQUATION 
It is also of importance to work side by side with the portions of metal under 
examination checks or standards, made of pure gold and pure palladium as nearly to 
the composition of the alloy to be tested as possible. 
The results by this process of quartation are very accurate. 
Platinum and Palladium. 
The first alloy operated upon in this next series was one of palladium and platinum, 
in proportions of— 
H. Palladium. 85 per cent. 
Platinum. 15 „ 
To ensure accuracy, the alloy was made from the pure metals in the spongy condi¬ 
tion, fused separately, and then alloyed in the foregoing proportions. 
The alloy was melted and re-melted in a lime furnace with oxyhydrogen gas, and 
cast into a mould, to ensure a complete mixture of the two metals. 
The alloy was then again remelted, and cast into a lime sphere of about 3 inches 
diameter. About 4 kilogs. of the alloy was made for this experiment. 
The sphere so produced was afterwards cut, and divided into two hemispheres. 
The alloy, which had been melted and cast at a temperature of about 2000° C., was 
decidedly brittle and of a dark grey colour, and the casting was slightly honeycombed 
from its centre to the tube, or “ gate,” through wdiich the metal had been poured into 
the mould. The alloy was very hard. 
In the lower portion of the sphere, shown by the dotted line, the peculiar bluish- 
purple characteristic of palladium showed itself as a distinct feature. 
Pieces cut from the places indicated showed the results respectively of palladium 
and of platinum. 
Alloy H. Palladium. 850 parts. 
Platinum ...... 150 ,, 
Parts in 1000 :— 
Outside. 
Intermediate. 
Centre. 
Palladium. 
Platinum. 
Palladium. 
Platinum. 
Palladium. 
Platinum. 
835 
157-5 
830 
160 
845 
152-5 
850 
147-5 
835 
155 
845 
145 
840 
155 
855 
142-5 
837-5 
160 
842-5 
155 
Average . 845’5 
149-5 
835-6 
157-5 
Maximum difference between centre and mean of outside: Palladium, 5 per thousand; Platinum, 
30 per thousand 
