Page:Popular Science Monthly Volume 9.djvu/353

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LESSONS IN ELECTRICITY.
331

LESSONS IN ELECTRICITY.[1]

HOLIDAY LECTURES AT THE ROYAL INSTITUTION.

By Prof. TYNDALL, F. R. S.

IV.

SECTION 17. History of the Leyden-Jar.—The next discovery which we have to master throws all former ones into the shade. It was first announced in a letter addressed on the 4th of November, 1745, to Dr. Lieberkühn, of Berlin, by Kleist, a clergyman of Cammin, in Pomerania. By means of a cork, C, Fig. 23, he fixed a nail, N, in a phial, G, into which he had poured a little mercury, spirits, or water, W. On electrifying the nail he was able to pass from one room into another with the phial in his hand and to ignite spirits of wine with it. "If," said he, "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."

In the following year Cunæus, of Leyden, made substantially the

Fig. 23. Fig. 24. Fig. 25.

same discovery. It caused great wonder and dread, which arose chiefly from the excited imagination. Musschenbroek felt the shock, and declared in a letter to a friend that he would not take a second one for the crown of France. Bleeding at the nose, ardent fever, a heaviness of head which endured for days, were all ascribed to the shock. Boze wished that he might die of it, so that he might enjoy the honour of having his death chronicled in the "Paris Academy of Sciences." Kleist missed the explanation of the phenomenon; while

  1. A course of six lectures, with simple experiments in frictional electricity, before juvenile audiences during the Christmas holidays.