ON THE PHYSICAL VIEW OF NATURE. 195 



or the wave theory of electricity, to deal with the prob- 

 lem of ether and matter ? In this combined scheme 57. 



What are 



what and where were the electric charges or units ? electric 



charges ? 



On the Continent the labours of Prof. H. A. Lorentz 

 of Leyden, and the almost simultaneous memoir of Von 

 Helmholtz, approached this subject from the side of 

 certain optical problems, notably the vexed question 

 whether the luminiferous ether ;is stagnant, or par- 

 ticipates in the movements of ponderable matter through 

 it, and the phenomena of dispersion. These writings 

 have formed the beginning of a long series of theoretical 

 and experimental researches, which are by no means 

 concluded. In this country we must chiefly consult 

 the many and highly interesting writings of Dr Larmor 

 for a fundamental discussion of the numerous problems 

 involved. At the same time we find there a very 

 thorough criticism, appreciation, and embodiment of the 

 many scattered suggestions and contributions of English 

 and Continental thinkers. Dr Larmor starts from a 5 g. 

 beginning which is peculiar to him. He finds among positio or 

 the older theoretical discussions of the nature of the 

 luminiferous ether one 1 which will permit of such an 



essay " On -<Ether and Matter," etrate a little deeper into the 



and W. Wien has quite recently nature of those building stones 

 introduced it for discussion at j and their mutual action " (loc. tit., 



the " Deutsche Naturforscherver- p. 56). 



sammlung" (Diisseldorf, 1898, Ber- J The historical traditions of Dr 

 icht i. p. 49). On the occasion of Larmor's theory seem to lie in 

 this discussion, Prof. Lorentz said : what may be called the Dublin 

 " Ether, ponderable matter, and, school of mathematical physics, 

 we may say, electricity, are the with the great names of Rowan 

 building stones out of which we Hamilton (vector analysis), Mac- 

 compound the material world, and Cullagh, and, in recent times, the 

 if we only knew whether matter, much lamented G. F. Fitzgerald, 

 in its motion, carries the ether "The form under which the 

 with it or not, a way would have atomic electric theory is intro- 

 opened by which we could pen- duced in Dr Larmor's latest essay 



