u Dr. C. R. Alder Wright. [June 2, 



alloys containing antimony instead of tin or silver absorbed oxygen 

 still more readily. In all such cases the analyses are calculated npon 

 the sTm of the aluminium, tin, and lead as 100 ; thus m the followmg 



instance : 



Directly Calculated on sum 



determined. as 100. 



Tin ...... 52-53 54-82 



" -16 B'52 



Aluminium ......... 35-12 36-66 



Iron ............... 0-99 



Silicon (total) ....... 0'51 



Oxygen (by difference) 2'69 



100-00 100-00 



Mixtures of Aluminium, Lead, and Tin. 



A number of ternary mixtures were prepared by melting alu- 

 minium, and then adding weighed quantities of lead and tin, and 

 stirring vigorously. A considerable amount of scoriae was usually 

 formed, the lead partially oxidising, and the presence of the lead 

 oxide formed causing the mass to " flour " considerably ; usually the 

 molten portion was run off into an ingot mould, and then re-melted, 

 and when in the pasty stage preceding complete fusion rubbed 

 about in the bottom of the crucible with a hot fireclay pestle, so as to 

 promote intermixture. Finally the temperature was raised, so as to 

 bring about complete fusion, and after more vigorous stirring the 

 liquid metal was poured into red-hot narrow clay crucibles or test- 

 tubes, and maintained molten in a lead bath for seven to eight hours 

 in the manner previously described. The temperature during this 

 period of tranquil fusion lay between 750 and 850, and averaged 

 close upon 800, as determined by the platinum specific heat 

 pyrometer (Part I). No flux of any kind was used during the 

 previous meltings and stirrings, oxidation being diminished as far 

 as practicable by directing a current of coal gas into the crucible ; 

 notwithstanding a much larger amount of oxidation usually took 

 place than with metallic mixtures fused together with potassium 

 cyanide, as in the previous experiments. The metal thus oxidised 

 was usually chiefly lead, the tin and aluminium present being com- 

 paratively unaffected ; the uncertainty as to the amount of lead 

 thus removed in any given case prevented any accurate calculation 

 being made respecting the relative weights of the three metals 

 present in the final compound ingot ultimately obtained ; the weight 

 of this was always considerably less than the joint weights of the 

 three metals originally used, partly through oxidation, but prin- 

 cipally because the formation of oxide led to a copious amount of 



