HISTORY 60

Department of History
University of California, Irvine
Instructor:    Dr. Barbara J. Becker

 

Week 7.  Natural Forces

excerpts from
The History and Present State of Electricity with Original Experiments (1769)
by Joseph Priestley (1733-1804)

 

Period VIII.  The History of Electricity, from the Discovery of the Leyden Phial in the Years 1745 and 1746, till Dr. Franklin's Discoveries.   (pp. 80-99)

THE end of the year 1745, and the beginning of 1746 were famous for the most surprising discovery that has yet been made in the whole business of electricity, which was the wonderful accumulation of its power in glass, called at first the LEYDEN PHIAL; because made by Mr. Cuneus [Andreas Cuneus (1712-1788)] a native of Leyden, as he was repeating some experiments which he had seen with Messrs. Muschenbroeck [Pieter van Musschenbroek (1692-1761)], and Allamand [Jean Nicolas Sébastien Allamand (c. 1716-1787)], professors in the university of that city.  But the person who first made this great discovery, was Mr. Von Kleist [Ewald Georg von Kleist (1700-1748)], dean of the cathedral in Camin; who, on the 4th. of November 1745, sent an account of it to Dr. Lieberkuhn at Berlin.  This account, as taken by Mr. Gralath [German physicist, Daniel Gralath (1708-1767)] out of the register of an academy at Berlin, to which it had been communicated, is as follows.

"When a nail, or a piece of thick brass wire, &c. is put into a small apothecary's phial and electrified, remarkable effects follow:  but the phial must be very dry, or warm.  I commonly rub it over beforehand with a finger, on which I put some pounded chalk.  If a little mercury or a few drops of spirits of wine, be put into it, the experiment succeeds the better.  As soon as this phial and nail are removed from the electrifying glass, or the prime conductor, to which it hath been exposed, is taken away, it throws out a pencil of flame so long, that, with this burning machine in my hand, I have taken above sixty steps, in walking about my room.  When it is electrified strongly, I can take it into another room, and there fire spirits of wine with it.  If while it is electrifying, I put my finger, or a piece of gold, which I hold in my hand, to the nail, I receive a shock which stuns my arms and shoulders.
"A TIN tube, or a man, placed upon electrics, is electrified much stronger by this means than in the common way.  When I present this phial and nail to a tin tube, which I have fifteen feet long, nothing but experience can make a person believe how strongly it is electrified.  I am perswaded, he adds, that, in this manner, Mr. Boze [German professor of natural philosophy at Wittenberg, Georg Mathias Bose (1710-1761) would not have taken a second electrical kiss.  Two thin glasses have been broken by the shock of it.  It appears to me extraordinary, that when this phial and nail are in contact with either conducting or non-conducting matter the strong shock does not follow.  I have cemented it to wood, metal, glass, sealing wax &c. when I have electrified without any great effect.  The human body, therefore, must contribute something to it.  This opinion is confirmed by my observing, that, unless I hold the phial in my hand, I cannot fire spirits of wine with it."

NOTWITHSTANDING Mr. Kleist immediately communicated an account of this famous experiment (which indeed it is evident he has but imperfectly described) to Mr. Winckler at Lepsick Mr. Swiettiki of Dantzick, Mr. Krugar of Hall, and to the professors of the academy of Lignitz, as well as to Dr. Lieberkuhn of Berlin ..., they all returned him word, that the experiment did not succeed with them....

Professor Muschenbroeck and his friends, observing 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 these experiments with water, in glass bottles:  but no considerable discovery was made, till 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 it) was surprised by a sudden shock in his arms and breast, which he had not in the least expected from the experiment....

It is extremely curious to observe the descriptions which philosophers, who first felt the electrical shock, give of it; especially as we are sure we can give ourselves the same sensation, and thereby compare their descriptions with the reality.  Terror and surprise certainly contributed not a little to the exaggerated accounts they gave of it; and, could we not have repeated the experiment, we should have formed a very different idea of it from what it really is, even when given in greater strength than those who first felt this electrical shock were able to give it.  It will amuse my readers if I give them an example or two.

MR. MUSCHENBROECK, who tried the experiment with a very thin glass bowl, says, in a letter to Mr. Reamur, which he wrote soon after the experiment; 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, that he would not take a second shock for the kingdom of France.

The first time Mr. Allamand made this experiment (which was only with a common beer glass) he says, that he lost the use of his breath for some moments; and then felt so intense a pain all a long his right arm, that he at first apprehended ill consequences from it, though it soon after went off without any inconvenience.  But the most remarkable account is that of Mr. Winckler of Leipsic.  He says, that the first time he tried the Leyden experiment, he found great convulsions by it in his 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 an heaviness in his head, as if a stone lay upon it.  Twice, he says it gave him a bleeding at his nose, to which he was not inclined; and that his wife (whose curiosity, it seems, was stronger 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.

We are not, however, to infer from these instances, that all the electricians were struck with this panic.  Few, I believe, would have joined with the cowardly professor, who said that he would not take a second for the kingdom of France.  Far different from these were the sentiments of the magnanimous Mr. Boze, who with a truly philosophic heroism worthy of the renowned Empedocles, said he 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 it is not given to every electrician to die in so glorious a manner as the justly envied Richman [Russian scientist, Georg Wilhelm Richmann (1711-1753), who was killed by lightning while investigating its electrical nature].

It was this astonishing experiment that gave eclat to electricity.  From this time it became the subject of general conversation.  Every body was eager to see, and, notwithstanding the terrible account that was reported of it, to feel the experiment; and in the same year in which it was discovered numbers of persons, in almost every country in Europe, got a livelihood by going about and showing it.

While the vulgar of every age, sex, and rank were viewing this prodigy of nature and philosophy with wonder and amazement; we are not surprized to find all the electricians of Europe immediately employed in repeating this great experiment, and attending to the circumstances of it.   Mr. Allamand remarked, that, when he first tried it, he stood simply upon the floor, and not upon cakes of rosin.   He said, that it did not succeed with all kinds of glass; for that though he had tried several, he had had perfect success with none but those of Bohemia, and that he had tried English glasses without any effect at all.   Professor Muschenbroeck at that time only observed, that the glass must not be all wet on the outside.

It is no wonder that so few of the properties of glass charged with electrical fire were known at first, notwithstanding the attention that was immediately given to the subject by all the electricians in Europe.  The experiment is, to this day, justly viewed with astonishment by the most profound electricians:  for, though some remarkable phenomena of it have been excellently accounted for by Dr. Franklin, and others, much remains to be done; and in many respects, the circumstances attending it are still inexplicable.  What will result from more attention being given to it, time only can show....

Mr. Gralath [in Germany] ... found, that the same shock could be communicated to a number of persons, who took hold of one another's hands; if the person at one extremity of the line they made, touched the outside of the phial, and he at the other touched a wire communicating with the inside.  In this manner, on the 10th. of April 1746, he gave a shock to twenty persons; and he says he did not doubt, but it might be given to a thousand....

[Dr. Watson; English scientist (1715-1787)] suggested a ... method ... of accumulating and increasing the force of charged glass, far beyond what was expected from the first discovery of it.  This method was, coating the outside of the phial, very near to the neck, with sheet lead, or tinfoil.  When a bottle was prepared in this manner, and nearly filled with water, they observed, that a person who only held in his hand a small wire communicating with that coating, felt as strong a shock as he would have felt, if his hand had been in actual contact with every part of the phial touched by the coating....

It is curious to observe in what manner Dr. Watson explained the shock of the Leyden phial, about the time that he first made the experiment with it.  He had then been led ... to the notion both of the afflux, and efflux of electrical matter in all electrical experiments.  To apply this principle to the case in hand, he supposed, that the man who felt the shock parted with as much of the fire from his body, as was accumulated in the water and the gun barrel; and that he felt the effect in both arms, from the fire which was in his body, rushing through one arm to the gun barrel, and through the other to the phial.  He imagined also, that as much fire as the man parted with was instantly replaced from the floor of the room, and that with a violence equal to the matter in which he lost it....

Afterwards ... Dr. Watson changed his opinion about this afflux and efflux of electric matter, with a generosity and frankness becoming every inquirer after truth, he retracted this hypothesis....

In France as well as in Germany experiments were made to try how many persons might feel the shock of the same phial.  The Abbé Nollet ... gave it to one hundred and eighty of the guards, in the King's presence; and at the grand convent of the Carthusians in Paris, the whole community formed a line of nine hundred toises, by means of iron wires between every two persons ... and 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.

MR. NOLLET also tried the effect of the electric shock upon two birds, one of which was a sparrow, and the other a chaffinch, which, as far as I can find, where the first brute animals of any kind that ever received it.  The consequence was, that upon the first shock, they were both instantaneously struck motionless, and, as it were, lifeless, though for a time only; for they recovered some few minutes after.  Upon the second shock, the sparrow was struck dead, and, upon examination, was found livid without, as if it had been killed with a flash of lightning; most of the blood vessels in the body being burst by the shock.  The chaffinch revived as before.  Fishes were also killed with the electric shock, by the Abbé, and others.

The circumstance of the blood vessels of the sparrow being burst is, I imagine, a mistake.  I have seen no such effect, when smaller animals have been killed by a shock fifty times as great as it is probable, the Abbé used upon this occasion.

 
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