180 



Outlines of the Mineralogy and Geology 



The taste is earthy. 



It adheres strongly to the tongue. 



Xt soils. 



Its streali is similar but lighter. 



It is friable. 



It is very soft. 



The fracture is from coarse to fine earthy. 



It is easily frangible. 



The fragments are indeterminately angular, 



Chymical Character. 



Before the blowpipe it fuses into a black or dark green enamel. 



Geological Situation and Localities, 



Clay exists in vast quantities in the vicinity of Boston, as at 

 Charlestown, Dorchester, Cambridge, Dauvers, &c. 



Use. 



The purest occurs at Danvers, where it is extensively manu- 

 factured into the coarser kinds of pottery. The irapurer varieties 



« 



are employed for making bricks. 



