MINERALOGY. 87 



ing and boiling heat, and of holding falts and 

 acids, can be made. It is found, 



1. Pure, P::ra. 



A. Biiiuiible in water. 



1. Coherent and drv. 



a. White, from Japan. 



I have feen a root of a tree changed 

 into this clay. (Appendix, Section 

 cclxxxiii.) 



2. Friable and dry. 



a. White, is found in clefts of rocks at 

 Wefterfllfverberget in Weftmanland, 

 and between the coal, in the coal- 

 pits at Boferup, in the province of 

 Skone *, 



2. Mixed with phlogifton, and a very fmall 

 quantity of infeparable heterogeneous fub- 

 itances, 'Terra porcellanea phlogifio aliifque 

 betercgeneis minima pcrtione mixta. Of thefe 

 are, 



A. DifFufible in water, 



a. White and fat pipe clay, from Cologne 

 and Maeflricht. 



Left unctuous is found in fmall fif- 

 fures in a vein of lapis ollaris, at Swart- 

 v/ik, in the pariiri of Swerdfio, in the 

 province of Dalarne. 

 h. Of a pearl colour, from Maeflricht. 



c. Bluifh grey, La belle terre glaifefro-n 

 Montmartre, near Paris, in France. 



d. Grey, France, HeiTe, Bofempin, Skone. 



* Thefe may be called pure, fince after being burnt, they 

 are quite wh;te, though they have been expofed to a quick 

 melting heat ; and it may be queried, if all fuch clays mull 

 ttpt be fomewha; harm, or at ieaft not uncluous to the 

 iou;:.. 



G 4 e f Black, 



