(30 MEMORIAL OF JOSEPH HENRY. 



latter mode into practical and most successful execution. If Henry 

 had patented his discovery, which he was urged, but declined to do, 

 Mouse could have patented only his alphabetical mode of signaling, 

 and perhaps the use of relay-batteries, the latter indispensable for 

 long lines upon that system. 



The scientific as well as popular effect of Professor Henry's 

 first paper in Silliman's Journal was immediate and great. With the 

 same battery that STURGEON used he developed at least a hundred 

 times more magnetism. The instantaneous production of magnets 

 lifting four hundred and twenty times their own weight, of those 

 which with less than a pint of dilute acid acting on two hands' 

 breadth of zinc would lift seven hundred and fifty pounds, and 

 this afterward carried up to a magnet lifting thirty-three hundred 

 pounds, was simply astonishing. Yet it was not these extraordinary 

 result.-, nor their mechanical applications which engaged Professor 

 Henry's attention so much as the prospect they opened of a way 

 by which to ascend to higher discovery of the laws of nature. In 

 other hands, his discoveries furnished the means by which diamag- 

 netism, magnetic effects on polarized light, and magneto-electricity — 

 now playing so conspicuous a part — soon came to be known. In 

 his own hands, the immediate discovery of the induction of a cur- 

 rent in a kmg wire on itself* led the way to his next fertile field 

 of inquiry, the following up of which caused unwise tardiness in 

 the announcement of what he had already done. For it is within 

 our knowledge that the publication of the paper which initiated his 

 fame had been urged for months by scientific friends, and at length 

 was hastened by the announcement of some partly similar results 

 reached in a different way by Moll, of Utrecht. In a letter not 

 long afterward written to one of us, Professor Henry had occasion 

 to declare: "My whole ambition is to establish for myself and to 

 deserve the reputation of a man of science." Yet throughout his 



■ Announced in American Journal ..i Science and the Art-- in 1S32 



