An epitome of electricity & galvanism

by Jacob Green; Erskine Hazard

In 1745, the attention of Dr. Watson being attracted by the account of the Germans having fired spirits of wine, he applied himself to electricity with much assiduity, and made many valuable and curious discoveries. But though his improvements were considerable, and such as at another time would have excited interest, they were now lost amid the surprise occasioned by the most remarkable discovery that had yet been made in the whole science. This was the accumulation of the electric matter in glass bottles, and the method of giving the electric shock.

The merit of this discovery belongs to Mr. Cuneus, a native of Leyden, from whence it derives its name of the Leyden phial.[^[7]] “M. Muschenbroeck, professor in the university in that city, observing with his friends, that electrified bodies, exposed to the common atmosphere, which is always replete with conducting particles of various kinds, soon lost their electricity, and were capable of retaining but a small quantity of it, imagined, that were the electrified bodies terminated on all sides by original electrics, they might be capable of receiving a stronger power, and retaining it a longer time. Glass being the most convenient electric for this purpose, and water the most convenient non-electric, they first made their experiments with water in glass bottles; but no considerable discovery was made, till the professor, or Mr. Cuneus, happening to hold his glass vessel in one hand, containing water, which had a communication with the prime-conductor by means of a wire, and with the other hand disengaging it from the conductor (when he imagined the water had received as much electricity as the machine could give) was surprised by a sudden shock in his arms and breast, which he had not in the least expected from the experiment.”

Wonder is the effect of ignorance, and ignorance begets credulity; but when wonder and credulity are coupled with terror and surprise, we must look for a strange and mishapen progeny. The exaggerated accounts of those who first experienced the electric shock cannot but raise a smile; especially as we may ascertain their real sensations by like experiments upon ourselves.

Mr. Muschenbroeck, in a letter to Mr. Reaumur, written soon after the Leyden discovery, says; that he felt himself struck in his arms, shoulders, and breast, so that he lost his breath; and was two days before he recovered from the effects of the blow and the terror. He adds, he would not take a second shock for the kingdom of France. Mr. Allamand who tried the experiment with a common beer glass, affirmed, that he lost the use of his breath for some moments; and then felt so intense a pain along his right arm, that he at first apprehended ill consequences from it, though it soon after went off without any inconvenience. But the terror of Mr. Winckler of Leipsic exceeded that of all the rest. The first time he tried the Leyden experiment, he says, he found great convulsions by it in his whole body: and that it put his blood into great agitation; so that he was afraid of an ardent fever, and was obliged to use refrigerating medicines. He also felt a heaviness in his head, as if a stone lay upon it. Twice, he says, it gave him a bleeding at the nose, to which he was not inclined; and that his wife (whose curiosity, it seems, was greater than her fears) received the shock only twice, and found herself so weak, that she could hardly walk; and that a week after, upon recovering courage to receive another shock, she bled at the nose after taking it only once.

Mr. Boze, with other philosophers were, however, far from participating in the cowardice of the professor of Leipsic. They gathered resolution to receive a number of electric shocks, as strong as they could be given. Mr. Boze, indeed, as Dr. Priestley remarks, “with a heroism worthy of Empedocles, wished he might die by the electric shock, that the account of his death might furnish an article for the memoirs of the French academy of sciences. But, adds the same author, it is not given to every electrician to die the death of the justly envied Richman.”

This experiment, calculated, not only to engage the investigation of the philosopher, but to raise the vulgar amazement, brought electricity into general notice.—From this time every body was eager to see and to feel this prodigy of nature; and numbers of persons, travelling over Europe, gained a livelihood by exhibiting its appearances and effects. At the same time, all the electricians were zealous to search into the nature of this extraordinary phenomenon. Dr. Watson prosecuted experiments to ascertain how best to succeed with the Leyden phial. He observed that the force of the shock was not increased by the size or number of the globes employed in filling it; nor by increasing the quantity of water in the vessel; but that the power was greatest when the glass was thinnest, and the water warmer than the ambient air. He was proceeding with these discoveries, when Mr. Bevis informed him that he found the electric explosion as great from covering the sides of a pane of glass, as it could have been from a half pint phial of water. The Doctor upon this coated large jars with leaf silver, both inside and outside, within an inch of the top, and from the greatest explosion he produced from them, drew the conclusion that the effect of the Leyden bottle was owing, not so much to the quantities of non-electric matter contained in the glass, as to the number of points of non-electric contact within the glass, and the density of matter of which these points consisted.

In France, the Abbè Nollet attempted to measure the distance to which the electric shock might be carried, and the velocity with which it passes. At one time he electrified 180 of the guards in the king’s presence; and at another the whole community of the grand convent of the Carthusians at Paris, forming a line of 900 toises, by means of iron wires between every two persons; when the whole company, upon the discharge of the phial, gave a sudden spring at the same instant of time, and all felt the shock equally.

But these attempts of the French philosophers to measure the electric circuit were insignificant, in comparison with the extended and numerous experiments of Dr. Watson, accompanied by a number of English gentlemen of eminence. Those gentlemen, in their first attempt, conveyed the electric shock across the river Thames; making use of the water of the river as a part of the chain of communication. This was accomplished by fastening a wire all along the Westminster bridge, at a considerable height above the water. One end of this wire communicated with the coating of a charged phial, the other being held by an observer, who, in his other hand, held an iron rod which he dipped into the river. On the opposite side of the river stood a gentleman, who likewise dipped an iron rod into the river with one hand, and in the other held a wire the extremity of which might be brought into contact with the wire of the phial.

Upon making the discharge, the shock was felt by the observers on both sides of the river, but more sensibly by those who were stationed on the same side with the machine; part of the electric fluid having gone from the wire down the moist stones of the bridge, thereby making several shorter circuits to the phial; but still all passing through the gentlemen who were stationed on the same side with the machine.—This was, in a manner demonstrated, by some persons feeling a sensible shock in their arms and feet, who only happened to touch the wire at the time of one of the discharges, when they were standing upon the wet steps which led to the river. In one of the discharges made upon this occasion, spirits of wine were kindled by the fire which had gone through the river.

They afterwards undertook to determine whether the electric virtue could be conveyed along dry ground, and to distinguish, if possible, the respective velocity of electricity and sound.