[ 247 ] 



Four parts Stronthian lime, and one of filex, heated to 138", 

 partly hardened and partly melted ; but as the crucible was 

 confiderably aded upon, the genuine efFedls of thefe propor- 

 tions is not clear. 



Three parts Stronthian lime and one part argill, heated to 

 150°, melted into a black compaft mafs, of which the upper 

 part was an enamel, and the lower a porcelain, not having been 

 fufEciently heated. The fame experiment made with common 

 lime produced only a porcelain. 



Two parts Stronthian lime and one of argill, heated to 150®, 

 melted only where in contadl with the crucible, the interior 

 parts retained its powdery ftate ; common lime ufed inftead of 

 Stronthian remained alfo in powder. 



Equal parts Stronthian lime and magnefia retained their pow- 

 dery ftate, except where in conradl with the crucible. 



Four parts filex and one of Stronthian remained unaltered 

 at 147'', though the influx of melted coal feemed to convert 

 them into a greyifh black compadl porcelain. 



A COMPOUND formed of 67 parts filex, 23 of argill, and 10 

 of Stronthian lime, melted at fo low a heat as 114° into a 

 greyilh white porcelain, which in a heal of 147° only became 

 porous. When common lime was ufed inftead of Stronthian the 

 compound melted at 145" into a femitranfparent frothy ena- 

 mel. 



