PHILOSOPHICAL SOCIETY OF WASHINGTON. 251 



and securing by its more tangible remunerations tlie leisure and 

 the means for more extended researches, would not have been to 

 science more than a compensation for the supposed sacrifice of 

 dignity by the philosopher.* 



Nov did this repugnance to patenting arise (as it sometimes 

 does) from any theoretical disapproval of the system. On the 

 contrary, he frequently expressed his strong conviction that a 

 judicious code of patent laws — if faithfully administered — fur- 

 nishes the most equitable method of recompensing meritorious 

 inventors. The institution was a good one — for others. 



i77?e discovery of Magneto-electricity. — From the magnetizing 

 influence of the galvanic current, physicists were almost inevi- 

 tably led to expect the converse reaction; and this anticipation 

 appears to have been coeval with electro-magnetism. As early 

 as 1820, the illustrious Augustin Fresnel remarked : " It is natu- 

 ral to try whether a magnetic bar will not produce a galvanic 

 current in a helical wire surrounding it;" and he made various 

 experiments to determine a question which was supposed to 

 involve the soundness of Ampere's theory. In November 1820, 

 he announced that though he at first supposed his attempt at the 

 magneto-electric decomposition of water was partially successful, 

 he was finally satisfied that no decisive result was obtained.')' 



Five years later, Faraday attempted the same experimental 

 inquiry; and among his earliest publications gave an account of 

 his unsuccessful trials. After describing his arrangements he 

 says : " The magnet was then put in various positions and to 

 different extents into the helix, and the needle of tlie galvanometer 

 noticed : no effect however upon it could be observed. The cir- 

 cuit was made very long, very short, of wires of different metals 

 and different diameters, down to extreme fineness, but the results 

 were always the same. Magnets more and less powerful were 

 used. . . . Hence it appears that however powerful the 

 action of an electric current may be upon a magnet, the latter 

 has no tendency by re-action to diminish or increase the intensity 

 of the former. "J 



Nor were American physicists discouraged by the records of 

 repeated failures: and when the great Henry magnet was re- 

 ceived at Yale College, Professor C. U. Shepard (Chemical 

 Assistant to Professor Silliraan) at once attacked the problem 

 with this new equipment. He remarks; "As its magnetic flow 



* Several hundred patents have since been granted in tliis country for 

 ingenious modifications of — or improvements upon the electro-magnetio 

 telt'grapii ; and probably a luindred for equally ingenious varieties of tlie 

 electro-magnetic enijine ; all of which would have been tributary to 

 Henry as an original patentee. 



j- Annales de Chlmie et de Physique, 1820, vol. xv. pp. 219-222. 



% Quarterly Journal of Science, July 1825, vol. xix. p. 338. 



25 



