NATURAL 
was corroded by the nitre. But by 
heating nitre with fome thin pieces 
of pure platina, in acup of the fame 
metal, I found that the platina was 
eafily diffolved ; the cup being much 
corroded, and the thin pieces en- 
tirely deftroyed. By diffolving the 
faline matter in water, the greater 
part of the platina was precipitated 
in the form of a brown powder. 
This powder, which was entirely 
foluble in marine acid, confifted of 
the calx of platina, combined with 
a portion of alkali, which could not 
be feparated by being boiled in 
water. The platina, which was re- 
tained bv the alkaline folution, 
communicated to ita brown yellow 
colour. By adding an acid to it, a 
Poet was formed, which con- 
{ted of the calx of platina, of alkali, 
and of the acid which was em- 
ployed. 
Silver, I found to be a little cor- 
roded by nitre. But, as its action 
upon that metal was very inconfi- 
derable, it did not appear to be de- 
ferving of a more particular ex- 
amination. , 
° 
Objfervations and Experiments made to 
_ determine the fwifonous Qualities of 
_ Azote. By Eaglesfeld Smith, E/q. 
_ Member of the Society for the Encou- 
_ ragement of Arts, Sc. 
ROM the fatal confequences 
f which enfue to animals that 
breathe atmofpheric air deprived of 
‘its oxygenous principle, or that re- 
ceive into their ftomachs thofe fub- 
ftances which contain it either as 
their bafe or as a principal ingre- 
dient (under fome particular modi- 
fication) it appears to me to be the 
deftroying principle in all thofe 
poifons which kill the animal, by 
throwing it into convulfions; and 
- that it is the caufe of the pheno- 
HISTORY 393, 
mena which takes place in many of 
thofe difeafes to which mankind 
are fubject, or that it is the caufe 
of the difeafe itfelf. The following 
experiments will in fome meafure 
illuftrate the foregoing hypothefis. 
It is known, that many fubftances 
taken into the cavity of the ftomach 
(except in a very confiderable quan- 
tity) are not noxious, which when 
thrown into the circulating fyftem, 
even in the very fmalleft quantities, 
caufe the animal to expire in vio- 
lent convulfions. ‘The atmofpheric 
air taken into the ftomach of man 
or other animals, caufes violent vo- 
miting (See Goffe’s Experiments 
on himfelf and other animals); but 
its bafe, when injected into the 
circulating fyftem, is inftantaneous 
death. 
EXPERIMENT TI. 
I took two mice; one J caufed 
to be {tung by a wafp, which was 
immediately thrown into convul- 
fions, and expired in two minutes : 
into an incifion made into the muf- 
cular fubftance of the other, I in- 
jected two drops of the nitrous acid : 
it feemed to operate exaétly in the 
fame manner as the fting of the 
wa{p, and the animal expired im- 
mediately. On opening them, 
and endeavouring to ftimulate the 
mufcular fubftance of their hearts, 
I found it had, in a great meafure, 
loft its irritability. Fontana obferves, 
in his book upon poifons, that the 
nitrous acid applied to the mufcular 
fubftance of a pigeon, killed it im- 
mediately, Cavendifh and Lavoi- 
fier have proved by experiments, 
that the azote is the radical princi- 
ple of the nitrous acid, 
EXPERIMENT It. 
Having taken four frogs, I made 
incifions into the mufcular fubftance 
of three of them; into one I in- 
jected 
