ABSTRACT
The Greeks and Romans, and the whole of the thinking world down to the year 1600, knew only one fact connected with electricity proper–that two substances—amber and jet—when rubbed will attract light particles such as chaff, dust. The marvellous X-rays are also produced by means of electricity, though their exact nature is still unknown. In modern chemical analysis, electricity is very largely used, whether in the intense heat of the electric arc, which melts or volatilises the most intractable substances, or through decomposition produced by the voltaic current. When conveyed by conductors, the electric currents are limited to the surface of the wires, or they penetrate to a very small depth, while the internal part shows no sign of electricity. Although the fact that lightning sometimes magnetised knives and other pieces of steel had been occasionally observed, all attempts to produce the same effects by electricity had failed.
