1889.] 



On certain Ternary Alloys. 

 Series II. Temperature near 689 C 



467 



Besides these forty ingots, however, a number of others were 

 obtained, yielding numbers on analysis not agreeing at all well with 

 the forty, more especially as regards the lighter alloys. In all cases 

 the figures were just such as would be obtained if complete separation 

 by gravitation had not taken place, so that the lighter alloy retained 

 a little of the heavier one disseminated through it, and vice versa ; 

 just as when ether and certain aqueous liquids are agitated together, 

 a kind of froth forms, which takes a long time before it entirely 

 separates, forming two clear liquids. As the experiments subsequently 

 detailed render it certain that these abnormal ingots were simply 

 cases where the separation was imperfect, the figures obtained with 

 them are not included in the above tables, but it is obvious that this 

 same source of error may have applied to a lesser extent even to some 

 of the forty ingots not rejected. No doubt this was actually the case 

 in some instances, on which account the curves obtained on plotting 

 the above figures show a certain amount of sinuosity and irregularity. 

 The error from this cause, however, as subsequently shown, is not 

 serious ; so that the concordance between the curves got from the two 

 series of analyses respectively is sufficiently marked to show that no 

 very considerable influence is exerted by a difference of temperature 

 amounting to some 124, on the way in which a given mass of lead, 

 tin, and zinc divides itself on standing molten. 



Three noteworthy curves are thus obtainable : 



(a.) When the tin percentages in the heavier alloy are plotted as 

 abscissae and the zinc percentages as ordinates. 



