408 On the magnetic Phenomena 
I tried to gain similar results with currents of common elec- 
tricity sent through flame, and im vacuo. They were always af- 
fected by the magnet; but it was not possible to obtain so de- 
cided a result as with Voltaic electricity, because the magnet 
itself became electrical by induction, and that whether it was in- 
sulated, or connected with the ground*. 
IV. Metals, it is well known, readily transmit large quantities 
of electricity ; and the obvious limit to the quantity which they 
are capable of transmitting seems to be their fusibility, or vola- 
tilization by the heat which electricity produces in its passage 
through bodies. 
Now I had found in several experiments, that the intensity of 
this heat was connected with the nature of the medium by which 
the body was surrounded ; thus a wire of platinum which was 
readily fused by transmitting the charge from a Voltaic battery 
in the exhausted receiver of an-air pump, acquired in air a much 
lower degree of temperature. Reasoning on this circumstance, 
it occurred to me, that by placing wires in a medium much 
denser than air, such as ether, alcohol, oils, or water, I might 
enable them to transmit a much higher charge of electricity than 
they could convey without being destroyed in air; and thus not 
only gain some new results as to the magnetic states of such 
wires, but likewise, perhaps, determine the actual limits to the 
powers of different bodies to conduct electricity, and the relations 
of these powers. 
A wire of platinum of 74, of three inches in length, was 
fused in air, by being made to transmit the electricity of two 
batteries of ten zinc plates of four inches with double copper, 
strongly charged: a similar wire was placed in sulphuric ether, 
and the charge transmitted through it. It became surrounded 
by globules of gas ; but no other change took place; and in this 
situation it bore the discharge from twelve batteries of the same 
kind, exhibiting the same phenomena. When only about an 
inch of it was heated by this high power in ether, it made the 
ether boil, and became white hot under the globules of vapour, 
and then rapidly decomposed the ether, but it did not fuse. 
When oil or water was substituted for the ether, the length of 
the wire remaining the same, it was partially covered with small 
globules of gas, but did not become red hot. 
On trying the magnetic powers of this wire in water, they 
* IT made several experiments on the effects of currents of electricity si- 
multaneously passing through air in different states of rarefaction in the 
same and different directions, both from the Voltaic and common electrical 
batteries ; but I could not establish the fact of their magnetic attractions or 
repulsions with regard to each other; which probably was owing to the im- 
possibility of bringing them sufficiently near. 
were 
