252 BULLETIN OP THE 



was SO powerful, I had strong hopes of being able to accomplish 

 the decomposition of water by its means. My experiment how- 

 ever proved unsuccessful. ... I hope however to resume 

 the research hereafter, under more favorable circumstances."* 



Henry, unsatisfied with past efforts, determined to pursue the 

 subject in an exhaustive series of experiments ; and had reached 

 some momentary indications of the galvanometer, when his ex- 

 periments were temporarily interrupted. Meanwhile it was an- 

 nounced in May, 1832, that Faraday had secured the long sought 

 prize ; though the announcement was brief, and to those eager 

 for particulars, somewhat disappointing. Henry was accord- 

 ingly induced to publish in the following number of Silliman's 

 Journal (that for July) a sketch of his own trials both before 

 and after the announced discovery. With reference to Faraday's 

 discovery he remarks : " No detail is given of the experiments, 

 and it is somewhat surprising that results so interesting, and 

 which certainly form a new era in the history of electricity and 

 magnetism, should not have been more fully described before this 

 time in some of the English publications. The only mention I 

 have found of them is the following short account from the Annals 

 of Philosophy for April, under the head of Proceedings of the 

 Royal Institution. — 'Feb. 17. Mr. Faraday gave an account of 

 the first two parts of his researches in electricity ; namely volta- 

 electric induction, and magneto-electric induction. . . . If a 

 wire connected at both extremities with a galvanometer, be coiled 

 in the form of a helix around a magnet, no current of electricity 

 takes place in it. This is an experiment which has been made 

 by various persons hundreds of times, in the hope of evolving 

 electricity from magnetism. But if the magnet be withdrawn 

 from or introduced into such a helix, a current of electricity is 

 produced while the magnet is in motion, and is rendered evident 

 by the deflection of the galvanometer. If a single wire be 

 passed by a magnetic pole, a current of electricity is induced 

 through it which can be rendered sensible. 'f 



"Before having any knowledge of the method given in the 

 above account, I had succeeded in producing electrical effects in 

 the following manner, which differs from that employed by Mr. 

 Faraday, and which appears to me to develop some new and 

 interesting facts. A piece of copper wire about thirty feet long 

 and covered with elastic varnish, was closely coiled around the 



* Silliman's Am. Jour. Sci. April, 1831, vol. xx. p. 201, foot-note. 



t Philosoph. Mag. and Annals of Phil. April, 1S32, vol. xi. pp. 300, 

 301. Although Faraday's first communication on galvanic iniluction, 

 and on magneto-electricity, was read before the Royal Society November 

 24, 1831, tlie published Transactions for 1832, containing this memoir 

 did not reach this country till more than a year later : so that the meager 

 abstract of the Royal Institution Proceedings above given, was the only 

 notice of this important discovery, — here accessible for many months. 



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