LIFE AND LETTERS OF FARADAY 435 



to cling with particular affection to this discovery. He 

 felt that there was more in it than he was able to unfold. 

 He predicted that it would grow in meaning with the 

 growth of science. This it has done; this it is doing 

 now. Its right interpretation will probably mark an 

 epoch in scientific history. 



Rapidly following it is the discovery of Diamagnetism, 

 or the repulsion of matter by a magnet. Brugmans had 

 shown that bismuth repelled a magnetic needle. Here he 

 stopped. Le Bailliff proved that antimony did the same. 

 Here he stopped. Seebeck, Becquerel, and others, also 

 touched the discovery. These fragmentary gleams excited 

 a momentary curiosity and were almost forgotten, when 

 Faraday independently alighted on the same facts; and,' 

 instead of stopping, made them the inlets to a new and 

 vast region of research. The value of a discovery is to 

 be measured by the intellectual action it calls forth; and 

 it was Faraday's good fortune to strike such lode? of 

 scientific truth as give occupation to some of the best 

 intellects of our age. 



The salient quality of Faraday's scientific character 

 reveals itself from beginning to end of these volumes; a 

 union of ardor and patience the one prompting the at- 

 tack, the other holding him on to it, till defeat was final 

 or victory assured. Certainty in one sense or the other 

 was necessary to his peace of mind. The right method of 

 investigation is perhaps incommunicable; it depends on 



Uebereinstimmung derjenigen Geschwindigkeit, welche das Verhaltniss der 

 electro-dynaraischen Einheit zur electro-statischen ausdriickt, mit der Greschwin- 

 digkeit des Lichte angeregt worden; und mir scheinl von alien Versuchen^ 

 welche zur Verwirklichung dieser Hoffnung gemacht worden sind, das von 

 Herrn Maxwell demachte am erf olgreichsten. " 



