Mr Murray’s Experiments on the Ignition of Wires . 89 
doubt lost and expended therein, and in the great temperature 
developed at the same time. 
In connection with the subsequent detail, I may be permitted 
to mention, that a ribbon of platinum foil, suspended from one 
of the conductors, and brought in contact with the mercurial 
surface (that metal being contained in a shallow glass-basin), 
while the other one is plunged into the mercury, deflagrates 
with great brilliancy, and oscillates like a pendulum. 
I may now state generally, that steel and platinum wires may 
be intensely ignited , in alcohol , ether and its vapour , oil of 
olives , naphtha and. sulphur et of carbon. I have not succeeded 
in igniting these in water , and conclude that it is owing to the 
superior conducting property of that fluid. The degree of igni- 
tion, all circumstances being the same, will correspond with the 
relations in which the medium containing the wire stands to 
conduction. 
Platinum and steel wires may be ignited in carbonic acid-gas , 
hydrogene , cyanogene, and olefiant gas. 
Gold-wire was wrapped round platinum in all its extent ; and 
this double wire placed as the uniting wire between the conduct- 
ing rods. It was ignited throughout, and the fusion of the gold- 
wire supervened, the gold being collected into little spheres of a 
prolate form, at equal distances, and appearing like a row of 
beads. 
Steel-wire was, in like manner, entwined with gold-wire. It 
also was ignited in its whole extent ; the gold- wire was fused, 
and exhibited the bead-like form. 
Platinum was woven with copper- wire. The platinum- wire 
was ignited throughout ; the copper-wire not undergoing fusion, 
nor even ignition. 
Jt may here be remarked, that, in the ignition and combustion 
of steel-wire, for instance, the fusion is primarily confined to the 
surface , and the fused scale or film may, perhaps, not penetrate 
more than J the diameter of the wire, while the remaining part 
may not have undergone the least physical change. The fused 
matter formed itself into spherules, with regular intervals. This 
appears to me to be a curious phenomenon ; and it will also be 
observed, that when the calorific effect is short of ignition, the 
steel-wire will be blued in patches. 
