The enquirer. [volume] (Richmond, Va.) 1804-1815, 1811-08-27
oeiniens aad seseala.iens q ~. Dayy

-The opinions advanced by MIR Davy, during
the present lectures at the Royal Institution, re-
Eating 10 combustion, and the nature OF heat and
light vary so much from the received doctrines,
and are so interesting and important, that we
shall here en6eavor to give an abstract of them
from his different lectures
Combustion, according to these new doc
ttines, is not the result of tho combination of
oyygen with other bodies, by which the oxygen
is condensed and the light and heat given out,
rs the French chemists assert; nor are heat
and light specific substances, differing from O..
Their matter. An bodies which have a strong
chemical gffinity or attraction for each other,
arc luund to possess two different states ofelec.
trici,v Thus. acids are negative, and the aka
lies positive Zinc and mercury, and other me-
Gals which possess strOnH chemical afhoIties.
are siso ia different states OF electricity. This
difference IN the natural states OF electricity,
DIR. Dayy considered as the cause of chemicsl
afinil, Combustion is the effect Of chemical
action n such bodies as combine rapidly 30.
getI,er, the particles violently agiated and,
bsine separated from each other by their polar
repuisiOns, are thrown OF in straight lines hro'
free spsce, and become radiant heat and light.
Accoidieg to DIR. Davy, the PARTICLES Of ali bo-
dies possess polarity. With many bodies cxy-
geo has o most powerful affinity, and combines
with great rapidly and, during this violent
chemical action, much light and heat are pro
duced Some Of the French chemists have as.
serted, that oxygen is the only support of com,
bustion, and that the light and heat given out
cones from the oxygen alone. But Light and
heat arc produced in variety oiinstances with.
cut the presence ofoxygen. Indeed, IN all cases
where bodies rapidly combine, the phenomena
ofcombustion take place. The new metal pc.
tsssium, or the metal OF po;ass, was placed IN a
glass vessel filed with carbCnic acid gas by
the heat of spirit lamp applied to the glass,
the metal inhamed IN tbis gas, and gave out 3
brilliant light. Charcoal WAS deposited on the
side ofthe glass In this experiment, it may
be sid, that tue oxygen Of the carbonic acid
oonbined with the potassium but IL ought to
be recoecied, that this oxygen had given out
its light end heat, according to LaYoisier, when
X combined with charcoal to form carbGnic gas.
II ought not therefore to give out second time
,shat IL had before lost.-ln another expert.
r1eut potassium aud arsenic were placed ia q
clos retcrt, containing nitrogen gas by the
hest of the spirit lamp they combined rapidly,
snd. during the cnmaiDstoa, much light and
heat were produced Here, II the experiment!
,Vas ugope ry made, no oxygen was present.
1getsls also inHame spontaneously an chlorine
gss. Improperly called o2ymgrlatic scid gas J
Ji1s sas, Dr Dayy STATED, was q simple un
compounded Substance, containing no oxygen.
HIS egperiuiefits on ibis subject VIC shall after
tusrds mention Heat is rsdiated froua the sur
faces Of all bodies, but in different degrees, a.
cord're 10 their nature end color. Black sur-j
faces absorb and slso emit radiant heat noreJ
randy lhon others If a polished surface on
metal ana On equal sarisce Of charcoal, bel
heated 10 he same degree, snd thermometer
he ulse,d at tie same distance from esci, tlci
chart viii raise the Thermometer more raj
tn,,ii, 4. =. polished metal This radiAiion1
nFhcsf . Leslie bad attributed % certain ae. /
rial u,,lsst,ous. DIR. Dayy stated, this could not
sz the CASE, for heat was more powerfully ia.