GALVANISM. 
tina wire-was made to touch the ignited alkali. A violent 
a€tion took place; a brilliant light was obferved on the ne- 
gative _ as if fome combuttible matter were aoa 
and burned ag it was evolved; when the fpoon was negative, 
on ae globules were feen 16 rife to the furface, and inflame 
on contact with air. He then made ufe of potath, flightly 
: re to the air: the potafh was ee 
upon a plate of platina co onneéted’ with the negative fide of 
the battery, and # plato wire from the other end of the 
battery was brou in contact with the upper furface of 
2a ie effervefcence took fae oar igs wire 
upper furface; no gas appe 
furface ; but {mall soe, having igh aie Iu, and 
the general appearance of quickiilver, began appea 
Some of thefe glo obules burnt in the air with sens ie 
bright flame ; maincd, becoming tarnifhed, and 
Thefe metallic glo- 
e fubflance for which Mr. Davy 
‘hich 
Be 
io 
was, 
e€ politive wire, and the eae 
bafe to i negative fae (See Porasu and ALKALi, and 
Phil. Tranf. for 1808, parti. page By a fimilar pro- 
cefs, Mr. Davy decompofed foda, ammonia, and feveral of 
the earths ; refolvi ing them, into oxygen and peculiar inflam- 
mable bafes. 
An extenfive field is here opened for chemical refearch, 
too vaft for human conception, by the introduction of this 
powerful agent. More difcoveries have been made in one 
year, than, perhaps, ard ene century can n boaft. 
a) 
ae) 
Ss 
9 
oa 
i=} 
a 
ta 
cee 
a.) 
>i 
ct 
o> aap 
a2 
“oO 
a 
? 
rought 
into to camad, pa a a ‘ibabonee in ae ae cleric . 
b 
tt 
for initance, if a plate of copper be brought in cont 
ion of electricity is tranfmitted 
the latter pofitive 
If the plates have infulated han- 
be ihe wn-by Bennet’s ecoe 
that filver and zinc, or copper 
of Galvani olta, the aan of the pile, took ad 
tage of the above faG to ex the phenomena. Int 
of this apparatus, t 
_conduGting medium ae om ne of 
Volta, however, himfelf ree wledges, lee when he m: 
es water as the conneétin edium, he ad the fame 
antity of. ewer indicated 
a interpofed fluid contained common an sitho 
fhock, in the firft ice, was {carcely perceptible, while, in 
the lattes it was very fevere 
Mr. c has lately gape an oe in Ni- 
cholfon’s tone al, which is to be continued, in he 
has proved that the quantity of wle€hricity Sadiested by the 
=) 
plates to another. 
bee the: 
= tg aot an see salen ang part. of the Gals. 
is account of the chemical. 
soenes of ledsicty already given, has endeavoured to- 
account e Galvanic effect on the principle of contact, 
without eae any of the effect to the chemical actions o 
the fubftances employed. He confiders the firft effet to be 
produced by the conta of the diflimilar metals, the zinc 
acquiring excefs, and the copper becoming deficient. The 
elements of the water employed, he fuppofes, are in the 
fame unequal ftate, by, eing in Saat ; the oxygen’ 
pote deficient or negative, and the hydrogen redundant or 
tive Ifa neutral falt be employed he alfo fappofes that 
the acid and alkali are Ag aoa difp Oe din their Sag: 
e zinc plat 
action of a battery confifting of the above arrangement, the 
jag iui fo far from being the caufe of - eletrical 
energy, e confidered as the means of reftoring th 
eg between the bodies in different ftates. ice 
e Zi nc, form 
e hydro en repairs to 
$c 
he 
ftate to itfe This 
ate 
of the procefs the bafe of the falt and the oxyd of zinc. are 
attracted to the copper furface, while the pase of the falt is: 
pore a to the zinc plate; the former tending to annihi- 
late the negative rie a copper, and the latter the po- 
fitive gee a the zinc plat , 
d be prefet in the jaa oe a hag which~ 
is ere ‘of decompofiti elem contrary 
ftates, and have ane reheat fim ae to oe ahah mr if theacid 
is not decompofed, it can only contribute to the procefs by 
diffolving the zinc. In the cee experiments of Mr. 
avy, he has fhewn that ac d oxygen become ne- 
gative by being brought in in contac with alkalies, earths, and 
inflammable matter, in ae fam a certain metals alter 
thei ir tates. saa oF 
ame time, 
ds in a gr 
employed, -and nee in 
water. A metallic 
meafure u ie 
n 
f zinc and copper, wit 
fluid - 
atic acid were a dded s the water. 
no perceptible Galvanic effect will be perceived, while in 
the latter a very fevere thock may be felt. ~ 
avy's doctrine the clerical. jan 
not ds 
pe fed, and of courfe cannot contribute to the effea. “Tei it 
thcrefore does no more than diffolve the onyd of zinc, it aad ee 
a 
