34 



On the Liquation of certain Alloys of Gold. 

 Fia. 11. 



Very marked separation takes place in both instances, the differ- 

 ences at various points of the sphere being very remarkable and 

 forcibly illustrating the difficulties to which reference is made at the 

 commencement of this paper. 



As, however, it appears, that when a certain amount of silver is 

 present, the irregularity in composition disappears, I alloyed this 

 mixture of 



Zinc . . 

 Lead. . 

 Silver 

 Gold., 



10 



20 



7 



63 



with more silver, so that it contained 15 per cent, of silver (nearly 

 half the united amounts of zinc and lead present in the alloy). 



This, cast into the 3-in. spherical mould, showed the following 

 results at the points indicated. In appearance, the metal, when sawn 

 in two, was homogeneous. The weight of the sphere was 3'459 kilo- 

 grams. 



FIG. 12. 



