76 SCIENTIFIC THOUGHT. 



Faraday are used merely for the sake of describing and 

 calculating in the simplest manner phenomena which 

 had been experimentally discovered : no attempt was 

 made to explain physically how these actions come 

 about. In fact, under the hands of Thomson the con- 

 ceptions of Faraday were formulated as Dal ton's atomic 

 theory had been elaborated by chemists in the first half 

 of the century, for the purpose of symbolically represent- 

 ing and calculating observed phenomena. 



But the " lines of force " of Faraday were not to remain 

 a mere symbolical representation, any more than Dal ton's 

 atoms were to remain merely counters of a chemical arith- 

 metic. Both theories were to be raised to the rank of 

 physical theories. What the kinetic theory of gases did 

 for the atomic theory was done for Faraday's symbolism 

 47. by the researches of Clerk Maxwell. And as the fact 



Clerk 



Maxwell. that the molecules of matter could be really counted, 

 and their distances and velocities measured, gave life and 

 actual meaning to the atomic view of natural phenomena, 



In his early geometrical researches from important errors (loc. cit., vol. 

 he worked in ignorance of the re- ii. p. 460), and which were later 

 markable ' Traite" ' of Poncelet, made more widely known in Ger- 



which had been published in 1822 

 (loc. cit., vol. i. p. 594, &c.) : even 

 the writings of his countryman 

 Mobius were unknown to him. 

 Still more extraordinary was his 

 comparative unacquaintance with 

 the electrical measurements and 



many by the excellent treatise of 

 his pupil Beer ( ' Einleitung in die 

 Elektrostatik,' &c., Braunschweig, 

 1869), posthumously edited by 

 Pliicker himself. The fact that 

 Pliicker was not influenced by the 

 spirit of Weber's researches prob- 



theories which dominated German ably made him more appreciative of 

 research when he commenced his j Faraday's purely physical methods, 

 physical labours, and which eman- | In such names as Beer, Clebsch, 



ated from the school of Gauss and 

 Weber. But he was equally ignor- 

 ant of the purely mathematical 

 theories of Poisson and Thomson, 

 which, as he himself candidly con- 

 fessed, might have saved him 



Klein, Fessel, Geissler, and Hittorf, 

 Pliicker counts an illustrious array 

 of pupils and fellow-workers. See 

 Clebsch's characteristic of Pliicker, 

 loc. cit., vol. i. p. xii, &c 



