634 
MR. EDWARD MATTHEY ON THE LIQUATION 
E. Gold . 
Platinum 
250 parts. 
750 „ 
Parts of gold in 1000 :— 
Outside. 
Intermediate. 
Centre. 
249-3 
245-5 
249-2 
250-2 
245-4 
248-7 
248-3 
251-7 
244 
251-6 
248 
Average . 249 "9 
Maximum difference in the gold between centre and outside, 2'5 per thousand. 
Maximum difference in the gold between intermediate and outside, 7'7 per thousand. 
251-7 
758 
It will be observed that in the spheres D and E, in which platinum constitutes the 
bulk of the mass, the platinum is still driven to the centre. This point requires 
further investigation ; but it may be pointed out that the same effect occurs in the 
case of standard silver. The most fusible alloy of the copper-silver series is the one 
which contains about 650 parts of silver in 1000, and it might, therefore, be expected 
that the centre of an alloy containing more silver than 65 per cent, would be poorer 
in silver than the outside; nevertheless, the authorities, Levol, Poberts-Austen, 
and in fact, all who have worked with silver-copper alloys know the contrary to be 
the case. Silver is driven inwards notwithstanding the fact that an alloy poor in 
silver remains fluid long after the mass as a whole has become comparatively solid. 
The platinum-gold alloys now in question behave like the silver-copper series. 
