Into the ears of all about:
So that the auditors may gain
Their meaning from the breach of cane.”
References.—Priestley, “History,” etc., 1775, p. 374, and Dantzig Memoirs, Vol. I. p. 294.
A.D. 1745.—Grummert (Gottfried Heinrich), of Biala, Poland, first observes the return of the electric light in vacuo. In order to ascertain whether an exhausted tube would give light when it was electrified, as well as when it was excited, he presented one eight inches long and a third of an inch wide, to the electrified conductor, and was surprised to find the light dart very vividly along the entire length of the tube. He likewise observed that some time after the tube had been presented to the conductor, and exposed to nothing but the air, it gave light again without being brought to an electrified body (see Dantzig Memoirs, Vol. I. p. 417).
A.D. 1745.—Dr. Miles (Rev. Henry), of Tooting, D.D. (1698–1763) reads, March 7, before the English Royal Society a paper indicating the possibility of kindling phosphorus by applying to it an excited electric without the approach of a conducting body. This gentleman’s tube happening to be in excellent order upon this occasion, he observed, and doubtless was the first to notice, pencils of luminous rays, which he called coruscations, darting from the tube without the aid of any conductor approaching it.
In a paper which Dr. Miles read before the same Society on the 25th of January, 1746, he gave an account of other equally interesting experiments, one of which was the kindling of ordinary lamp spirits with a piece of black sealing wax excited by dry flannel or white and brown paper.
References.—“Dict. Nat. Biog.,” Sidney Lee, Vol. XXXVII. p. 378; Phil. Trans., Vol. XLIII. pp. 290, 441; Vol. XLIV. pp. 27, 53, 78, 158, and the following abridgments: Hutton, Vol. IX. pp. 107, 136, 191, 198, 207, 213, 232; John Martyn, Vol. X. part ii. pp. 272, 277, 317, 319, 322–323, 325.
A.D. 1745.—This period was to witness a discovery which, according to Professor Tyndall, “throws all former ones in the shade,” and which Dr. Priestley calls “the most surprising yet made in the whole business of electricity.” This was the accumulation of the electric power in a glass phial, called the Leyden jar after the name of the place where the discovery was made. It was first announced in a letter to Von Kleist, dean of the cathedral of Kamin—Cammin—in Pomerania, dated the 4th of November, 1745, and addressed to Dr. Lieberkühn, who communicated it to the Berlin Academy. The following is an extract: “When a nail or a piece of thick brass wire 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 spirit 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 has 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.”
It is said that Cunæus, rich burgess of Leyden, accidentally made the same discovery in January 1746. It appears that Pieter Van Musschenbroek, the celebrated professor, while experimenting with his colleagues, Cunæus and Allamand, observed that excited bodies soon lost their electricity in the open air, attributable to the vapours and effluvia carried in the atmosphere, and he conceived the idea that the electricity might be retained by surrounding the excited bodies with others that did not conduct electricity. For this purpose he chose water, the most readily procured non-electric, and placed some in a glass bottle. No important results were obtained until Cunæus, who was holding the bottle, attempted to withdraw the wire which connected with the conductor of a powerful electric machine. He at once received a severe shock in his arms and breast, as did also the others upon renewing the experiment. In giving an account of it to the great scientist, René de Réaumur, Musschenbroek remarked: “For the whole kingdom of France, I would not take a second shock.” Allamand states that when he himself took the shock “he lost the use of his breath for some minutes, and then felt so intense a pain along his right arm that he feared permanent injury from it.”