PHYSICAL AND LITERARY. 219 



Twenty four grains of magneiia in fine 

 powder were mixed with five ounces of the 

 cauftic ley in a fmall vial, which was imme- 

 diately corked and (haken frequently for four 

 hours. The ley was then poured off, and 

 the magnefia wafhed with repeated affufions 

 of water, and dried. It had loft about the 

 half of its weight, and when reduced to a 

 fine powder was readily diflblved by acids 

 with an effervefcence which was hardly per-' 

 ceivable : the alkali had therefore extraded 

 its air. I alfo threw fome frefti magnefia 

 into the ley which had been poured off, and 

 thereby rendered it perfedly mild and fimilar 

 to a fohjtion of fait of tartar •■fo that it ef- 

 fervefced brifkly with acids. 



With an ounce of the mild fpirit of fait 

 ammoniac, I mixed a dram of magnefia in 

 very fine powder which had been previoully 

 deprived, of its air by fire j and obferving that 

 the magnefia had a tendency to concrete into 

 a folid mafs, I fhook the vial very frequently. 

 After fome days the powder was increafed 

 to more than double its former bulk ; and 

 when the vial was opened, the alkaline fpirit 

 emitted a moft intolerably pungent fmell. 

 It hkewife floated upon water, but was not 



perfectly 



