FUSION AND SOLIDIFICATION 



79 



of the compound and crystals of antimony. These 

 eutectics are represented by the points a and c 

 in the figure, and between them rises the curve 

 showing the effect of the compound, which 

 exists in the pure state at b, the maximum of 

 the curve. 



In all the cases yet considered, the crystals 

 deposited consist either of a pure metal or else 

 of a pure chemical compound. Whichever it be. 



ubo 



lOOO 



900 



800 



700 



eoo 



500 



400 



3 CO 



the composition of any one crystalline species is 

 fixed and definite ; it does not vary continuously 

 when the composition of the mass of alloy is 

 altered, as does, for example, the composition of 

 the fused liquid. In Fig. 6, p. 75, the left-hand 

 branch of the curve gives the composition of the 

 liquid alloy which, at different temperatures, is in 

 equilibrium with crystals of pure silver, while 

 the right-hand branch represents the liquid in 

 equilibrium with pure copper. One phase only, 



