542 On certain Ternary Alloys. [Feb. 2 r 



Antimony 17*50 



Bismuth 22-75 



Zinc 5975 



100-00 



Here the bismuth and zinc are in proportions near to those indicated 

 by the formula BiZn 8 ; with tin, silver, and cadmium as solvent 

 metals the corresponding proportions were respectively near to those 

 indicated by BiZn 10 , BiZn 3 , and BiZn 5 . 



It is noticeable that the limiting point thus deduced is the highest 

 point of the entire curve ; whereas, in every one of the other eleven 

 curves so far investigated, the limiting point lies on one side or the 

 other of the highest point, and more or less lower down. 



Two remarkable irregularities are visible in the contour of the 

 above-deduced critical curve for antimony-bismuth-zinc alloys ; on 

 the right-hand side a peculiar notch or depression is noticeable, 

 strongly suggesting a phenomenon similar in character to that pre- 

 viously observed in the case of silver- zinc-lead and silver-zinc-bismuth 

 alloys ; i.e., the formation of a definite compound of solvent with one 

 of the two immiscible metals more soluble in the other of these two 

 metals than any other neighbouring mixture of the two in other pro- 

 portions. On the left-hand side an analogous, but far wider, de- 

 pression is observable. These depressions reach their greatest depths 

 at the 7th tie line, where at each of the two conjugate points the 

 ratio between the bismuth and antimony present is not far from that 

 corresponding with the formula 



Experiments now in progress indicate that an analogous depression 

 exists in the critical curve obtained with antimony-bismuth- aluminium 

 alloys, also most strongly marked at a point where the bismuth and 

 antimony are in proportions not far from that corresponding with 

 Bi 3 Sb 2 . 



On comparing together the two curves deduced with antimony a 

 solvent it is noticeable that they show the same general characters as 

 t he corresponding pair of curves similarly obtained with cadmium as 

 solvent ; i.e., whilst the curve with bismuth as heavier immiscible 

 metal lies inside that with lead (as in all other similar cases as yet 

 examined), the direction of slope of tie lines is opposite in the two 



