A History of Science-2 [106]
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 Europe, and the whirling, 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.