PHYSICAL ann LITEARRY. 319 
_ dually increafed; when the veffels were cool- 
‘ ed, I found in the receiver, two ounces four 
_drams and a half, of an acid liquor, of a 
- faint greenifh colour, which fmoked much 
when the veffels were firft disjoined; but the 
fumes were paler.and whiter than thofe of 
fpirit of nitre, and fooner ceafed. I puta 
few drops of this liquor into a folution of fil- 
ver in aqua fortis ; it made it white and crud- 
dled, and at length a white powder fell down. 
I poured a fmall quantity of it upon a few 
grains of filings of gold; with the affiftance 
of a little heat, the fpirit pretty quickly dif- 
folved it, leaving only a’ few particles at the 
bottom. From thefe characters I think we 
_ may conclude, that the acid liquor, produ- 
ced in this operation, is a true agua regia: 
I chufe rather to call it fo, than fpirit of fea 
- falt; becaufe I found it had a greater and 
quicker effect in diffolving gold than the plain 
» fpirit of falt had, therefore it is probable, 
_ that a {mall quantity of the nitrous acid had 
_ accompanied the acid of fea falt. 
ij _ THERE remained in the retort, a cake of 
- folid white falt, like melted nitre, or /al pru- 
_ nellac: after it had been diffolved in warm 
water, the folution filtered and evaporated ; 
there 
