LUDOLFF'S EXPERIMENT WITH THE ELECTRIC SPARK
But Bose was only one of several German scientists who were
making elaborate experiments. While Bose was constructing and
experimenting with his huge machine, another German, Christian
Friedrich Ludolff, demonstrated that electric sparks are actual
fire--a fact long suspected but hitherto unproved. Ludolff's
discovery, as it chanced, was made in the lecture-hall of the
reorganized
scientists and great personages, at the opening lecture in 1744.
In the course of this lecture on electricity, during which some
of the well-known manifestations of electricity were being shown,
it occurred to Ludolff to attempt to ignite some inflammable
fluid by projecting an electric spark upon its surface with a
glass rod. This idea was 646u2016g suggested to him while performing the
familiar experiment of producing a spark on the surface of a bowl
of water by touching it with a charged glass rod. He announced to
his audience the experiment he was about to attempt, and having
warmed a spoonful of sulphuric ether, he touched its surface with
the glass rod, causing it to burst into flame. This experiment
left no room for doubt that the electric spark was actual fire.
As soon as this experiment of Ludolff's was made known to Bose,
he immediately claimed that he had previously made similar
demonstrations on various inflammable substances, both liquid and
solid; and it seems highly probable that he had done so, as he
was constantly experimenting with the sparks, and must almost
certainly have set certain substances ablaze by accident, if not
by intent. At all events, he carried on a series of experiments
along this line to good purpose, finally succeeding in exploding
gun-powder, and so making the first forerunner of the electric
fuses now so universally used in blasting, firing cannon, and
other similar purposes. It was Bose also who, observing some of
the peculiar manifestations in electrified tubes, and noticing
their resemblance to "northern lights," was one of the first, if
not the first, to suggest that the aurora borealis is of electric
origin.
These spectacular demonstrations had the effect of calling public
attention to the fact that electricity is a most wonderful and
mysterious thing, to say the least, and kept both scientists and
laymen agog with expectancy. Bose himself was aflame with
excitement, and so determined in his efforts to produce still
stronger electric currents, that he sacrificed the tube of his
twenty-foot telescope for the construction of a mammoth
electrical machine. With this great machine a discharge of
electricity was generated powerful enough to wound the skin when
it happened to strike it.
Until this time electricity had been little more than a plaything
of the scientists--or, at least, no practical use had been made
of it. As it was a practising physician, Gilbert, who first laid
the foundation for experimenting with the new substance, so again
it was a medical man who first attempted to put it to practical
use, and that in the field of his profession. Gottlieb Kruger, a
professor of medicine at Halle in 1743, suggested that
electricity might be of use in some branches of medicine; and the
year following Christian Gottlieb Kratzenstein made a first
experiment to determine the effects of electricity upon the body.
He found that "the action of the heart was accelerated, the
circulation increased, and that muscles were made to contract by
the discharge": and he began at once administering electricity in
the treatment of certain diseases. He found that it acted
beneficially in rheumatic affections, and that it was
particularly useful in certain nervous diseases, such as palsies.
This was over a century ago, and to-day about the most important
use made of the particular kind of electricity with which he
experimented (the static, or frictional) is for the treatment of
diseases affecting the nervous system.
By the middle of the century a perfect mania for making
electrical
machines had spread over
hand-rubbed globes were gradually replaced by great cylinders
rubbed by woollen cloths or pads, and generating an "enormous
power of electricity." These cylinders were run by belts and
foot-treadles, and gave a more powerful, constant, and
satisfactory current than known heretofore. While making
experiments with one of these machines, Johann Heinrichs Winkler
attempted to measure the speed at which electricity travels. To
do this he extended a cord suspended on silk threads, with the
end attached to the machine and the end which was to attract the
bits of gold-leaf near enough together so that the operator could
watch and measure the interval of time that elapsed between the
starting of the current along the cord and its attracting the
gold-leaf. The length of the cord used in this experiment was
only a little over a hundred feet, and this was, of course,
entirely inadequate, the current travelling that space apparently
instantaneously.
The improved method of generating electricity that had come into
general use made several of the scientists again turn their
attention more particularly to attempt putting it to some
practical account. They were stimulated to these efforts by the
constant reproaches that were beginning to be heard on all sides
that electricity was merely a "philosopher's plaything." One of
the first to succeed in inventing something that approached a
practical mechanical contrivance was Andrew Gordon, a Scotch
Benedictine monk. He invented an electric bell which would ring
automatically, and a little "motor," if it may be so called. And
while neither of these inventions were of any practical
importance in themselves, they were attempts in the right
direction, and were the first ancestors of modern electric bells
and motors, although the principle upon which they worked was
entirely different from modern electrical machines. The motor was
simply a wheel with several protruding metal points around its
rim. These points were arranged to receive an electrical
discharge from a frictional machine, the discharge causing the
wheel to rotate. There was very little force given to this
rotation, however, not enough, in fact, to make it possible to
more than barely turn the wheel itself. Two more great
discoveries, galvanism and electro-magnetic induction, were
necessary before the practical motor became possible.
The sober Gordon had a taste for the spectacular almost equal to
that of Bose. It was he who ignited a bowl of alcohol by turning
a stream of electrified water upon it, thus presenting the
seeming paradox of fire produced by a stream of water. Gordon
also demonstrated the power of the electrical discharge by
killing small birds and animals at a distance of two hundred
ells, the electricity being conveyed that distance through small
wires.
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