C 55 ] 



CLASS IL 



EARTHY SALTS. 



1 . Epsom Salt. 



Vitriolic Acid combined with Magnefia. 



Synonymous Names. 



'Bitter purging fait. 



1. EPSOM SALT. 



Magnefian vitriol. 

 Salt of fedlitz. 

 Sulphate of magnefia. 



It was formerly obtained from wells in the 

 neighbourhood of Epfom, and in the hills that 

 run to the eaftward of that place, whofe waters 

 contain it abundantly. It has a very bitter tafte, 

 is very foluble in water, and is very apt to form 

 fhort needle-like cryfials, when haftily cryftaliz 

 ed ; otherwife they are quadrangular prifms, ter- 

 minating in quadrangular pyramids. 



A. The magnefian bafis may be detected 

 a. By the addition of lime water, to water 

 containing this fait, which renders it turbid, and 

 a flaky precipitate will be gradually formed. 

 Lime has a ftronger affinity to vitriolic acid than 

 magnefia, combines with it and forms gypfum, a 

 fmall portion of which remains diflblved in the 

 water, the reft is precipitated along with the 

 magnefia. 



♦ b. A 



