CHINA CLAYS. 123 



The chemical analysis of the material is as follows: 



Analysis af China Clou near Kumulga, Talladega Co. (No. 205.) 



Silica 50.45 



Alumina 35.20 



Ferric oxide .80 



Lime 60 



Magnesia .62 



Alkalies 



Ignition 12.40 



100.07 

 Total fluxes 2.02 



The clay would no doubt work for the manufacture 

 of white tile; or white earthenware, but could not be 

 used for porcelain without being washed. 



(No. B. S.) 

 CHINA CLAY, 



EUREKA MINE, DEKALB CO. 



It is whitish clay, with little or no grit, and of re- 

 markable purity. In water it breaks up slowly to 

 small grains. 



It took 33 per cent, of water to temper it, and gave 

 a lean mass, which shrunk 2 per cent, in drying, and 

 an additional 6 per cent, in burning, giving a total 

 shrinkage of 8 per cent. Air dried briquettes of the 

 clay had an average tensile strength of 25 pounds per 

 square inch, with a maximum of 27 pounds. 



Incipient fusion occurs at 2300° F. vitrification at 

 2500° F., and viscosity above 2700° F. 



The clay burns to a very white, smooth body. 



An analysis of the clay gave the following results : 



