1890.] 



On certain Ternary A Hoys. 



39 



fused for some time, so as to remove it from the sphere of action, 

 and thus facilitate the separation in the same kind of way that 

 removing the products of decomposition pari passu with their forma- 

 tion facilitates the decomposition by heat or the dissociation of 

 ordinary chemical compounds. 



After various trials, we found that the simplest way of effecting 

 this was to prepare a series of mixtures of equal weights of lead and 

 zinc and varying quantities of silver, and keep them fused for 

 about eight hours, as in Series I ; the compound ingots thus obtained 

 were then cut in two, and the lighter portions fused separately 

 without stirring for another period of eight hours, so as to be out 

 of contact with the heavier portions formed during the first fusion. 

 Similarly, the heavier portions were also fused separately. The 

 result of this treatment was that each lighter portion underwent. 

 a further separation into a small quantity of heavy alloy and a 

 much larger quantity of a lighter one ; and, conversely, each 

 heavier portion similarly separated into a small quantity of lighter 

 alloy, which floated, and a much larger amount of heavier alloy. On 

 repeating the operation, by cutting off the small quantity of heavy 

 alloy (or lighter) that had thus separated, and fusing again for 

 another eight hours, no further separation to any material extent 

 occurred in the generality of cases, indicating that the limit of 

 decomposition by fusion had been reached. Thus, for example, the 

 following figures were obtained in two experiments with the lighter 

 portions of the ingots first formed : 



Similar results were obtained in various other cases ; moreover, we 

 found that, if instead of weighing up equal quantities of zinc and 

 lead and a given proportion of silver, and fusing for eight hours, 

 and then separating the two crude alloys formed, and again fusing 

 the lighter alloy, a mixture of the three metals was made in about 



