go JDr. Pearson’s Experiments and Observations 
or 3 ounces, was atmospherical air, with a little carbonic 
acid. 
Nitric acid was poured, in the same quantity as before, into 
the retort. An effervescence immediately took place, which was 
succeeded by a transparent solution. The distillation yielded 
gaz of the same kind as before, but in smaller quantity, with 
white fumes, and white sublimate. When only about 4 drachms, 
by measure, of liquid remained in the retort, a little of it was 
evaporated ; and, when reduced to a solid matter, it turned 
black, and took fire, leaving a carbonaceous residue ; but, be- 
fore this, a margin of beautiful pink matter appeared. 
Nitric acid was poured, as before, into the retort, for the third 
time, but very little gaz ascended, and much less white fumes 
than before. The distillation proceeded, till about one drachm- 
measure of liquid remained in the retort: this being left to 
stand, prismatic crystals were formed in a very small quantity 
of liquid. These crystals did not taste sour, but sharp, and they 
reddened turnsole-paper. Adding a little soda to a part of them, 
to see whether I could form a neutral salt, I was surprised by 
the extrication of ammoniac. To another portion of crystals I 
added sulphuric acid, which disengaged nitric acid. A third 
portion of crystals, being exposed over a lamp, wholly evapo- 
rated, without leaving a mark behind. The remaining matter 
in the retort being examined, was found to be nitrate of am- 
moniac. It was plain that the nitric acid had, by parting with 
oxygen to the carbon of the oxide, formed carbonic acid. The 
carbon being thus carried off, of course the nitrogen and hy- 
drogen of the oxide uniting produce ammoniac ; which, uniting 
with the redundant nitric acid, composes nitrate of ammoniac ; 
but great part of the nitrate of ammoniac was carried off in the 
