S A L T S. 137

liquor through paper; evaporate and fet itby to cryftallize.

M

R K.

This has been commonly called Sal Rupellenfis,or Rochelle Salt. Like foluble Tartar, it is decom-pounded by acids, but does not, like that, liquifyon expofure to the air, and its purgative quality isweaker. It is given from an ounce to an ounce anda half as a mild purgative,

ALUMINIS PURIFICATIO.

PüRIFICATION OF AlüM.

Take of Alum one pound.

Chalk one dram by weight.Diftilled Water one pint.Boil a little, ftrain, and fet the liquor a-fide to cryftallize.

ALUMEN USTUM,Burnt Alum.Take of Alum half a pound.

Burn