330 On the Action of a Spiral Conductor, &c. 
with silk, and the several spires closely wound on each other, the 
calorimotor will be almost converted into a deflagrator. One end of 
the conductor being attached to a pole of the battery, and the other 
brought in contact with, or rubbed along the edge ofa plate of metal 
attached to the other pole, a vivid deflagration will be produced, 
even when the plates are immersed in a mixture contaming not more 
than one part of acid to five hundred parts of water. 
If a copper cylinder of about two inches in diameter, and four or 
five inches long, to serve as a handle, be attached to each end of the 
spiral by an intervening piece of copper wire and thin cylinders 
grasped with moistened hands, a series of shocks will be felt when 
one end of the conductor is drawn across the edges of the zine 
plates, the other end being in contact with the copper pole. 
Another method of producing the shocks, is to place the spiral 
between two batteries each of a single pair, so as to connect the cop- 
per of one with the zinc of the other. If the extreme poles of this 
compound arrangement be terminated by the copper handles, and 
these be brought in contact, holding one in each hand, a deflagration 
of the metal will be produced, and a thrilling sensation, scarcely sup- 
portable, felt in each arm. ‘The effect is much increased if the 
handles are rough: two cylinders of cast zinc terminating the poles, 
were found to produce the greatest effect when rubbed on each other. 
To exhibit these phenomena in a striking manner, a galvanic bat- 
tery of considerable size is required. 1 have used one for the pur- 
pose, containing about forty feet of zinc surface, estimating both 
sides of the plate. ‘This battery was first immersed for a short time 
in a strong solution of acid to dissolve the coating of oxide, and then 
removed to a vessel containing pure water. ‘The small quantity of 
acid adhering to the plates was sufficient to produce, by means of 
the spiral the deflagration of the metals, which would shock and snap 
for many hours in succession, while with a short conductor the bat- 
tery in the same state gave no signs of electricity. 
This will be found an economical method of exhibiting some very 
interesting experiments with the calorimotor. After having shown 
the ordinary heating powers of the instrument with strong acid, trans- 
fer the plates to a trough containing pure water, and the action of the 
coil may be shown for an almost indefinite time, at little or no ex- 
pense of zinc or acid. 
The spiral produces no increased effect when applied to a galvan- 
ic trough of one hundred four inch plates. If, however, a coil of 
