PHYSICAL AKD LITERARY. 173 



with a warm folution of that {alt. But it 

 does not feparate an acid from a calcarious 

 earth, nor does it induce the lead change 

 upon lime-water. 



Lastly, when a dram of it is digefled 

 with an ounce of water in a bottle for fome 

 hours, it does not make any the leaft change 

 in the water. The magnefia, when dried, is 

 found to have gained ten grains ; but it nei- 

 ther efFervefces with acids, nor does it fen- 

 iibly affedt lime-water. 



Observing tnagnefia to lofe fuch a re* 

 markable proportion of its weight in the fire, 

 piy next attempts were dire(5ted to the in- 

 veftigation of this volatile part, and, among 

 other experiments, the following feemed to 

 throw fome light upon it. 



Three ounces of magnejia were diftilled in 

 a glafs retort and receiver, the fire being 

 gradually increafed until the magnefia was 

 obfcurely red hot. When all was cool, I 

 found only five drams of a whitifli water iri 

 the receiver, which had a faint fmell of the 

 fpirit of hartfl:iorn, gave a green colour to the 

 juice of violets, and rendered the folutions of 

 forrofive fublimate and of filver very llightly 



turbid. 



