to Calcium and 



ium Metasilicates. 



21 



Table III. 



Inversion Temperature of Wollastonite- D topside Mix- Crystals. 



(Inversion point of wollastonite, 1190°.) 



No. 



of 

 Exper. 



Composition 



T ^ e Temper- 

 Heating 



ature 



1 \% MgSiOs (2-l£ diopside) 



2 1% MgSiOs (2"1£ diopside) 



Continuation of Exper. 1 

 0£ MsrSiOa 



1 hr. 

 2hr. 



lhr. 



3 1% MgSi0 3 {%'!% diopside) 

 2 r c MgSi0 3 (4-3^ diopside) 



. \ \% MgSiOs (Continuation ) 1 , 



4 \ 2% MgSi0 3 of Exper. 3) f i nr> 



5 8% MgSiOs (17 '3^ diopside) 1 hr. 



1221 c 

 1245 c 



1257-1263° 



1273-1300° 



1278-1280* 



6 8% MgSi0 3 (17 -3£ diopside) 



(Continuation of Exper. 5) 1 hr. 1298-1303 c 



7 Continuation of Exper. (5 1 hr. 1327-1343 c 



Fig. 6. 



Eesults. 



No change. 

 Inversion slight. 



Completely 



inverted. 

 Slightly " 

 Doubtful 

 Largely inverted 

 Much less ' ' 

 Separation of 

 diopside. No 

 inversion. 



Inversion 



doubtful. 

 " evident. 



Fig. 6 shows under what conditions an inversion point remains unaltered 

 after the formation of a solid solution. 



the solution of another substance according to the equation 



02 T 2 



A =— — (C. — C„) where A = the depression in the tem- 

 e 



perature, T = the absolute temperature of the inversion point in 

 the pure substance, I — its latent heat of fusion, C, — the con- 

 centration of the solution above the inversion point and C 2 = 

 the concentration of the solution below the point. 



