Brilliant_ The Evolution of Artificial Light - Jane Brox [39]
Scientists in Leiden (or Leyden), Holland, refined von Kleist's machine, and thereafter it was known as a Leyden jar. The most elaborate of the jars consisted of a water-filled glass container with an outer and inner coating of metal foil and metal filings at the bottom of the jar. It was capped with a cork or a wooden lid, from which a conductor—a metal rod, usually brass, topped with a metal ball—protruded. A metal chain hung into the jar from the lid. Experimenters could transfer the electric charge from a whirling globe to the protruding ball; the charge traveled down the rod and chain to the water and foil. A Leyden jar could retain its charge for several days, which, as historian Philip Dray notes, allowed experimenters "to move electricity about as part of a graduated process, not merely to see it as the sudden flash that occurred between objects in a friction experiment."
One of the first experimenters in Leiden found that the jar contained enough power to make his whole body quiver. "I advise you never to try [it] yourself," he wrote to a colleague, "nor would I, who have experienced it and survived by the Grace of God, do it again for all the kingdom of France." But many others across Europe and in America did try it in the succeeding decades. Men administered shocks to small animals and birds, to themselves and their wives; they suffered nosebleeds and fevers, convulsions and weakness. Still they experimented. Abbé Jean-Antoine Nollet, at the court of Louis XV at Versailles, in an effort to see how far a shock could travel, sent a charge through 180 soldiers who'd joined hands. He was satisfied to see that they all jumped in unison, and then he tried the experiment on 750 Carthusian monks, who, holding wires between them, formed a line 5,400 feet long. As the abbé sent the current through, they, too, all jumped at the same moment.
Experimenters made bells ring, set rum on fire, and sent sparks shooting around gilded picture frames. They generated "electric kisses" by suspending a young woman in the same way Gray had suspended his "dangling boy." They then invited men from the audience to kiss her on the cheek, and sometimes the charge was significant enough to crack teeth. Still, electricity remained "a vast country, of which we know only some bordering provinces," and its experimenters were thought to be dabbling in a toy science, for no one had yet found a practical application for its power.
Benjamin Franklin, one of the eighteenth century's most tireless "electricians"—a phrase he coined and by which electrical experimenters were then known—was "chagrined a little that we have been hitherto able to produce nothing in this way of use to mankind." He knew electricity's true power only too well, having received at least one considerable jolt. "I have lately made an experiment in electricity that I desire never to repeat," he explained in a letter to a friend in Boston.
Two nights ago, being about to kill a turkey by the shock from two large glass jars, containing as much electrical fire as forty common phials, I inadvertently took the whole through my own arms and body.... The company present ... say that the flash was very great, and the crack as loud as a pistol; yet, my senses being instantly gone, I neither saw the one nor heard the other; nor did I feel the stroke on my hand, though afterwards found it raised a round swelling where the fire entered, as big as half a pistol-bullet, by which you may judge