Ponderous Earth. ' 5 



hence it is fufible in earthen vefFels, even of 

 porcelain ; it is fcarcely affedted by fixed al- 

 kalis, but eafily melted and without effervef- 

 cence by borax or rnicrocofmic fak, or 

 calces of lead. 



Ponderous Earth. 



i ft * This may more conveniently be called 

 Barytes 9 when pure it is alib in the ftate of 

 lime, which it perfectly refembles in tafte, but 

 it requires nine hundred times its weight of 

 water to diffolve it in the temperature of 60? 



2 d * It is combinable with acids, but with 

 the nitrous and marine, it forms falts that 

 do not deliquefce, and with the vitriolic, a 

 fait much more difficultly foluble than gyp- 

 fum, it decompofes tartar vitrolate, an effedl 

 which no other Earth can operate. 



3 d - It is precipitable from the nitrous and 

 marine acids by the Pruffian Alkali, a pro- 

 perty which alfo diflinguiihes it from all 

 other Earths, 



4 th * In the dry way it ads and is afted 

 upon nearly as calcareous Earth, but it is 

 fomething more fufible by the mineral alkali, 

 Its fpecific gravity exceeds 4,000* 



B 



