1893.] 



On Certain Ternary Alloys. 



533 



Fig. 1 represents these values plotted on the triangular system, the 

 internal dotted line being the curve obtained for the temperature 

 650, with tin as solvent metal (Part V). The position of the limit- 

 ing point L deduced by Stokes' second method is that where A+A' 

 = 73-0, and B + B' = 5'8 ; whence- 

 Lead 36-5 , I 



Zinc .. 2-9 



Cadmium 60'6 



lOO'O 



This corresponds with a ratio between lead and zinc not far from 

 that indicated by the formula Pb 4 Zn, widely different from the cor- 

 responding ratios found when tin and silver were the solvent metals, 

 respectively close to PbZn 6 and Pb 2 Zn, 



The six tie lines, Nos. 4 to 9, all spring from points very close 

 together on the left-hand branch of the curve, although the respec- 

 tive conjugate points on the right-hand branch are widely divergent. 

 The centre of this cluster of points is near the point P, giving the 

 values 



Cadmium 22 



Lead 76 



Zinc 2 



100 



which figures represent a ratio between cadmium and lead close to- 

 that indicated by the formula Pb 2 Cd. 



2 N 2 



