In one experiment Musschenbroek suspended a glass phial of water from a gun barrel by a wire which went down through a cork in the phial a few inches into the water. The gun barrel, hanging on a silk rope, had a metallic fringe inserted into the barrel which touched an electrically charged glass globe. A friend who was watching him, a man named Cunaeus, happened to grasp the phial with one hand and the wire with another. Immediately he felt a strange and startling sensation—reportedly the first manmade electric shock in history.
Musschenbroek repeated what Cunaeus had done, this time using a small glass bowl as his “Leyden jar.” “I would not take a second shock for the King of France,” he said.
Van Kleist in Pomerania produced the same effect. He lined the inside and outside of his Leyden jar with silver foil, charged the inner coat heavily, connected it with the outer foil by a wire which he held in his hand—and felt a violent shock run into his arm and chest.
A Leyden jar could take any number of forms. Even a wine bottle would serve. The type used most frequently during the next few years was a glass tube, some two and a half feet long, and just big enough around so that a man might grasp it easily in his hand. The advantage of this size and shape was that it could most conveniently be electrified, which was then done by hand, by rubbing the glass with a cloth or buckskin. This simple device gave impetus to research on electricity throughout Europe. It also provided a new form of entertainment.
Performers went from town to town with their Leyden jars, giving spectators the thrill of receiving electric shocks, and extolling the marvels of “electrical fire.” Louis XV of France invited his guests to watch a novel spectacle arranged by his court philosopher, Abbé Jean-Antoine Nollet. The King’s Guard in full uniform lined up before the throne, holding hands. The first one was instructed to grasp the wire or chain connected to the Leyden jar. They all jumped convulsively into the air as an electric current passed through them.
In Italy some scientists tried to cure paralysis by electric shock, claiming moderate success. In May 1748, for instance, Jean-François Calgagnia, thirty-five years old, was given an electric shock from a simple cylinder-type Leyden jar. Since the age of twelve, his left arm had been so paralyzed he could not lift his hand to his head. After the first electrical treatment he at once raised his arm and touched his face. There is no record as to whether the cure was permanent.
After Franklin became aware of this phenomenon, he was agog to try experiments on his own. He wrote of his interest to a London friend, Peter Collinson, a Quaker merchant and member of the Royal Society. Collinson promptly sent him a glass tube, along with suggestions as to how it might be used for electrical experiments. This was all Franklin needed to get started.
He was not trained in scientific matters as were many of his European contemporaries. He was unfamiliar with scientific jargon, and could only write about what he was doing in everyday language. But he had those qualities that are innate in any scientist, with or without a university degree—an inquiring mind, patience, and persistence.
His experiments, beginning with the winter of 1746, covered a wide range. He melted brass and steel needles by electricity, magnetized needles, fired dry gunpowder by an electric spark. He stripped the gilding from a book, and he electrified a small metallic crown above an engraving of the King of England—so that whoever touched the crown received a shock!
His home was soon so crowded with curious visitors trooping up and down the stairs, he could hardly get any work done. He solved the problem by having a glass blower make tubes similar to his, passing them out to friends so they could make their own experiments.