GALVANISM. 
tube of water wires of a neg of brafs. Under 
this circumftance, sie the 
em were tarni 
s from fhe filver end than from the zinc. The 
ranged that the gafes were feparately 
collefted. On pea ae the gas from the filver end was 
found to be hydrogen, as before, and that from the zinc end 
oxygen. Their 1 were found to agree with the 
component parts of w: 
The Galvanic ee conieed in the decompofition of 
bodies, was further profecuted by Mr. Cruickfhank of 
Woolwich, He employed in his experiments a pile cont 
ing of from - to 100 pairs of plates of filver and zinc abou 
14 inch fqu 
"He. 
h water, was 
uncemented cork downwar 
he wires being connetted with the ends of the p 
with the fives 
the muriatic acid bev eee lived from fome muriatic 
falt in the water e 
With a view to py ese how far his conjeture was right, 
e filled he tube with diftilled water, containing an infufion 
of litmus. ‘The appearances, with refpeét to the evolution 
as, were fimilar to the laft experiment; but the flui 
in ae vicinity of the wire coming from the zinc end of the 
pile, became of a red colour, while the fluid about the 
other gradually loft its purple tinge, and became of a deeper 
blue. In fhort, an acid appeared to be produced about the 
former wire, and an alkali about the latter. An infufion o 
Brazil wood underwent a changes to 
an acid and an alkali. all thefe 
of filver was pedis tas when 
io which was precipitated 
ns the wire i om the filver end of the pile by the alkali 
which was produced. 
his ingenious experimenter, knowing that hydrogen in 
its nafcent ftate was capable of reducing moft metallic 
oxyds, filled the tube with a folution of acetat of lead, 
and found that the hydrogen . difappeared, being. 
loyed in the reduction of the m y this means he alfo 
obtained pure oxygen ga s. The fame was obferved when fo- 
lutions of Na of filver and se ar of copper were em- 
loyed. a folution t of a em- 
ployed in the an et the filv ae oxydated, the oxyd 
mbined with the muriatic seid = he a and liquor 
wa 
mmonia was 
ckfhank repeated the above experiments, but in- 
flead e filver wires, he inferted into the tube wires of gold. 
“The proportion of oxygen gas was now much greater than 
with the ‘fi ‘Iver wires, the gold wire not being fufceptible of 
oxydation in the procefs.. 
His next attempt was to coHect the gafes feparately; this 
he effected by a tube about ae — long, which was bent 
into the form of the lette rc V; the wires 
e old 
zinc fide became eer diffolved, and the fluid 
in Nie vicinity affumed a yellow colour. When the tube was 
opened, a itrong {mell of aqua regia was perceived. Sim 
lar phenomena were obferved when muriat of foda was em- 
loye 
Having tried the effet of Soca upon acid folutions 
of metals, he was induced to at effet was produced 
upon alkaline folutions, for this eee he added an excefs 
of ammonia to a folution of nitrat of filver 
eon the z 
= 
ey fubftance depolited 
oppofite wire, which he a ne sas nd t a 
eee filver of Berthollet. When an 
copper was employed, the copper cecaae placa 
upon the wire from the filver fide. 
._ In addition to the ingenious experiments made. 
Cruickfhank, ui are indebted to him for 
what is called t e Galvanic trough. i 
at 
trough w was n dtidean to a number 
wide ; each of thefe plates were c compound, 
of zinc, and the other of co 
his apparatus was found fo much more convenient in 
aking the different ae than the pile, that it was 
al boos ted in this country 
ough conftructed by Mr. Cruickfhank confifted of 
fifty oe ee of zinc and hit er, each plate be, 
{quare. ‘This trough was found ver 
fh A finall piece of ftee] wir 
the end of the trough as foon 
came in contact with a piece of metal conneéted wi ith ae 
3 
rig white colour, 
leaving a dark ftain upon the metal foueee by the gold 
ea 
Batteries of much larger fize were foon conftrudte : by 
different philofophers, by which it was found that all the 
metals, reduced into thin 
liant, — differently coloured 
t was in this ftage of progrefs of Galvanifm, ee fome 
cee peniied re{pecting the precife. nature - fluid. 
: which thefe furprifing effects were attributed. Althouck 
t was generally fuppofed the effects were purely eléAtrical, 
one were inclined to doubt the identity of the two fluids, 
particus- 
leaves, were ees with bril-. 
flam 
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