HERMANN VON HELMHOLTZ 



the great English physicist. 1 His words in opening 

 the lecture are so characteristic of Helmholtz him- 

 self as to merit quotation : ' The facts which he 

 [Faraday] discovered are universally known. Every 

 physicist, at present, is acquainted with the rotation 

 of the plane of polarisation of light by magnetism, 

 with dielectric tension and diamagnetism, and with 

 the measurement of the intensity of galvanic currents 

 by the voltameter, while induced currents act on 

 the telephone, are applied to paralysed muscles, and 

 nourish the electric light. Nevertheless, the funda- 

 mental conceptions by which Faraday was led to 

 these much admired discoveries have not received 

 an equal amount of consideration. They were very 

 divergent from the trodden path of scientific theory, 

 and appeared rather startling to his contemporaries. 

 His principal aim was to express in his new con- 

 ceptions only facts, with the least possible use of 

 hypothetical substances and forces. This was really 

 an advance on general scentific method, destined to 

 purify science from the last remnants of metaphysics. 

 Faraday was not the first, and not the only man, 

 who has worked in this direction, but perhaps no- 

 body else at his time did it so radically. But every 

 reform of fundamental and leading principles intro- 

 duces new kinds of abstract notions, the sense of 

 which the reader does not catch in the first instance. 

 Under such circumstances, it is often less difficult 



1 Trans . of the Chemical Society, p. 277. 

 212 



