Sir Kenelm Digby, and the rise of physical science in England Sir Thomas Browne, destroyer of errors His extraordinary electrical discoveries made with the sulphur Francis Hauksbee and his experiments on light and electricity. Foreshadowings of the identity of electricity and lightning Stephen Gray, charter-house pensioner. His remarkable discoveries in electrical conduction and insulation. 474 Supposed combustion of the human body by electricity. Dean Von Kleist and the discovery of the Leyden jar Freke and Winkler's suggestions of the identity of lightning and Norse punishment for tampering with the Compass John Baptista Porta Jerome Cardan. Gilbert's Terrella Gilbert's armed lodestones. PAGE 73 145 180 181 182 288 290 291 303 346 353 358 363 398 448 459 461 464 INTRODUCTION. THE intellectual rise in electricity is worthy of historical investigation, not merely because of the material results, actual and potential, which have come from it, but because it shows clearly anew the marvellous power of the human mind as an instrument of discovery, capable of correcting its own errors. Beginning with a single phenomenon, afterwards including effects all, for long periods, seemingly fortuitous and uncorrelated, this rise has involved questions of an interest second only to that which mankind has yielded to the great issues of life and eternity; questions which challenged the human understanding and compelled it to measure itself against them. From one fact it came to include many facts, from one conception grew many conceptions, coincidently with the increase in human learning, the broadening of human thought, and the development of human intelligence. The initial idea-the germ-found its lodgment in some brain existing at an epoch far beyond the limits of history. The discovery of amber in the ancient lake dwellings of Europe suggests the possible perception of it by pre-historic man. The accidental rubbing against the skins with which he clothed himself may have caused an attraction by the resin, thus electrified, of the light fur in sufficiently marked degree to arrest his attention. Between such a mere observation of the fact, however, and the making of any deduction from it, vast periods may have elapsed; but there came a time at last, when the amber was looked upon as a strange inanimate substance which could influence or even draw to itself other things; and this by its own apparent capacity, and not through any mechanical bond or connection extending from it to them; when it was recognized, in brief, that nature held a lifeless thing showing an attribute of life. This was more than a mere impression. It was an enigma demanding resolution, and thus endowed with inherent and eternal vitality. At some other time, perhaps not until after the advent of an Iron Age, a similar power to that of the amber was seen in the attraction of the lodestone for iron. Because of this similitude the ancients somewhat hazily imagined both effects to be essentially one. Progress in discovery concerning either was therefore progress in knowledge concerning both. This is also true from our modern point of view, for not only are the phenomena of magnetism and of electricity directly correlated and interconvertible, but the concept of magnetism perhaps most widely accepted at the present time, holds it to be merely an electric state; the condition of electricity in whirling or vortex motion. The attempt to account for magnetic attraction as the working of a soul in the stone led to the first attack of human reason upon superstition and the foundation of philosophy. After the lapse of centuries, a new capacity of the lodestone became revealed in its polarity, or the appearance of opposite effects at opposite ends; then came the first utilization of the knowledge thus far gained, in the mariner's compass, leading to the discovery of the New World, and the throwing wide of all the portals of the Old to trade and civilization. The predominance of the magnet in human thought was yielded to the amber, when the strange power of the latter was found to exist also in other things. The keen-eyed discoverers saw this new force annihilate time and space, and flash into light; pursued it even to its hiding-place in the clouds; beheld it grow from the feeble amber-soul into the mighty thunderbolt; watched it until the whole universe showed itself pervaded with it. |