Bose's initial prime conductor consisted of an assistant standing on a block of
resin (an effective insulator) holding a metal bar in one hand while touching the spinning globe with the other. The friction-generated charge would have flowed through the assistant to the metal bar and accumulated on the external surface of the bar. In effect, this was an extension of
Stephen Gray's 1730 Flying Boy demonstration, but with the addition of a metal conductor which, over time, became the only effective storage device. What was novel was Bose's use of metal (the bar) at a time when it had long been accepted that only
insulators (then called "electrics") could successfully accumulate
static electricity. Metal
conductors were known to dissipate any charge relatively quickly and the need to insulate charged objects from electrical contact with the earth was not well appreciated. Later experiments by other experimenters showed that it was not the mass of the prime conductor which set the limit of static accumulation so much as its exterior dimensions—since like-charges repel and so the cumulative effect only exists on the external skin of the conductor. For three years, from 1742 to 1745, Bose promoted the study of electricity in Germany, and became famous for spectacular experiments including one where he set alight alcoholic spirits floating on the surface of water via a spark generated by his friction machine which passed through the water. Since water and fire were seen as direct opposites, this created a minor sensation among the observers and became widely mentioned in scientific correspondence.
Electric Kiss Bose's "Electric Kiss" (also called "Electric Venus") demonstration was immensely popular with spectators, and it was little more than a variation on
Stephen Gray's "Flying Boy" demonstration. An attractive young lady was invited to stand on a block of insulating resin, and she was given a moderate static charge from a spinning globe. A young man from the audience was then invited to give her a kiss, and, in the process, the pair received a reasonable shock. This demonstration combined both the scientific illustration of
charge accumulation with the naughtiness of a stolen kiss, so it became a mainstay of all electrical showmen and scientific demonstrators.
Beatification One of the public demonstrations developed by Bose became known as "Beatification", Having experienced such a shock, he was naturally loath to hold the bottle in his hand again and he seems not to have been able to duplicate the experiment. When he advised his scientific correspondents, they were also naturally very wary of holding the jar, and for some time they failed to duplicate the experiment. He is known to have corresponded his finding to a: Dr Lieberkuhn in Berlin, Mr Winckler at Leipzig, Mr Świetlicki of Danzig and Mr Krugar of Hall as well as the professors of the
academy of Liegnitz. Von Kleist had been educated at the
University of Leyden, and it is now widely assumed that he would also have corresponded with fellow ex-students Andreas Cunaeus (a lawyer), and Prof.
Jean Allamand (professor of theology) at the University. Allamand attempted to duplicate the experiment with a glass of beer and eventually succeeded. Cunaeus and Allamand worked occasionally with the professor of physics at
Leyden University,
Pieter van Musschenbroek, on new electrical experiments, and it took time for them to discover the secret. They finally worked out the importance of the outside conduction surface provided by the hand, which was needed to prevent the development of electrostatic backpressure, and, as a result, it was the Leyden University experimenters who received the bulk of the credit.
Loss of Manuscripts In 1744, Bose published his major works on electricity in the form of pamphlets released in London and Paris. However, many of his manuscripts were later lost. He is now mainly celebrated for his spectacular demonstrations rather than for his scientific contributions. In 1757 he was elected a
Fellow of the Royal Society of London. In 1760, during the
Seven Years' War with Prussia, Bose was kidnapped from Wittenberg as a strategic asset, and taken to Magdeburg where he was held as a hostage. This, ironically, was the site of
Otto von Guericke's famous sulphur ball experiment. He died at Magdeburg two years later.
Published works •
Tentamina electrica in academiis regiis Londensi et Parisina primum habita omni studio repetita quae novis aliquot accessionibus locupletavit. (Wittenberg, 1744). This is a reprint of his inaugural oration and two other pamphlets. • Die electricität nach ihrer Entdeckung und Fortgang mit poetischer Feder entworfen. (Wittenberg, 1744) ::(in French) ''L'électricité son origine et ses progrès. Poème en deux livres.'' (Leipzig, 1754) •
Recherches sur la cause et sur la véritable téorie de l’électricité (Wittenberg, 1745) This contains his electrical theory which suggested (like
Abbé Nollet) that the phenomenon was dependent on the active flow of a fluid. •
Tentamina electrica tandem aliquando hydraulicae chymiae et vegetabilibus utilia. (Wittenberg, 1747) ==References==