342 Mr. Gregor’s Experiments on a mineral Subs ta)ice 
are white, and soluble in nitric acid. Phosphat of ammonia 
and soda produced a white precipitate. Oxalat, tartrite, and 
prussiat of potash did not affect it, nor did sulphat of soda. 
Ammonia was dropped into it, but the fluid preserved its 
transparency. But carbonat of ammonia instantly caused a 
white precipitate, which was not redissolved by an excess of 
the precipitant ; upon some of this subsided precipitate a con- 
centrated solution of potash was poured and shaken with it, 
but it was not sensibly diminished. But if after edulcoration it 
be dissolved in nitric acid, and potash be added, no precipitate 
is produced. 
Carbonat of potash causes a white precipitate when dropped 
into the aqueous solution of the scaly sublimate. 
The supernatant fluid was poured off and gradually evapo- 
rated, but it became repeatedly turbid, nor could I by means 
either of the filter or alcohol prevent a recurrence of the same 
effect. Nearly the same result takes place when carbonat of 
ammonia is used as the precipitant. 
Some of the white scales were moistened with sulphuric acid. 
No vapour arose. 
Some of the precipitate obtained by means of carbonat of 
potash from the watery solution of this substance, was, after 
sufficient edulcoration, dissolved in sulphuric acid ; the solution, 
on due evaporation, produced permanent crystals, some of 
which resembled alum, but others seemed to differ from it in 
•external character. Ammonia decomposed the solution of 
them in water, and a few drops of liquid potash dissolved the 
precipitated earth. The quantity was too small for further 
experiment. 
If distilled water be poured into the retort and boiled in it, so 
