'■'TO 
Mineral Subfiance from New South Wales. 
repeated with a foliation in aqua regia. Here the Pr.yflian lixi- 
vium, in whatever quantity it was added, cccafioned no preci- 
pitation at all (only the ufual bluifhnefs, arifing from the iron 
always found in the common acids) ; and pure alkali, added 
afterwards, precipitated the original white fubftance unchanged. 
The following experiments of precipitation by alkalies were 
made with the marine folution, before the effeft of an addition 
of nitrous acid had been difcovered ; and they were made with 
fo much care and attention, that it was not thought necefiary 
to repeat them afterwards. To obviate, as much as pofh'ble, 
the equivocal refults that might ante from water contained in 
the precipitants, the different alkalies were applied in the dryeft 
ftate I could reduce them to ; viz. pure fait of tartar , kept for 
fome time in a heat juft below rednefs ; cryftals of marine ah 
kali, melted and dried in the fame manner ; volatile alkali in 
cryftals, a little furplus acid being, in this inftance, previoufly 
added to the folution, to counteraft the water of cryftallization 
in the alkali ; fait of tartar caufiicated by quicklime, and 
haftily evaporated to drynefs ; the marine alkali 'caufiicated in 
like manner ; and the vapour of cavjhc volatile alkali arihng, 
with a very gentle heat, from a retort into a phial containing 
the folution. All thefe alkalies occafioned copious precipita- 
tions. All the precipitates, after wafhing and drying, were 
found to re-diflolve in marine acid ; and, from all thefe folu- 
lions, the original fubftance was precipitated, unaltered, on 
diluting them with water. 
In ftrong fire, from 142 to 156 degrees, this fubftance diT 
covers a much greater fuftbility than any of the known Ample 
earths. In a fmali veffel, made of tobacco-pipe clay, it melted, 
and glazed the bottom ; and on a bed of powdered flint, prefled 
Vol. LXXX. T t fmooth 
