2T)(> Iiitelligcnce and Miscellaneous Articles. 



to have written unless he had some discovery of his own to an- 

 nounce. Such announcements were made in language, it" not always 

 the most polished, yet certainly, to scientific minds, the most 

 pleasing, because the most simple. On looking through his papers 

 here collected, it seems that almost all his discoveries were crucial. 



He was essentially witty, if by wit is meant nimbleness in cor- 

 relating divers impressions. By viewing an idea from various 

 sides and combining those views, he produced a discovery, a solid 

 fact. 



He never wrote for the sake of writing; nor did he regard 

 physics as the application of mathematics to hypothetical matter. 

 His mind was in unison with Nature. He seemed to feel that 

 theorization should be the servant, not the master, of investigation ; 

 and hence his superiority in usefulness over most of his contem- 

 poraries. 



The publication of this collection of memoirs by the Physical 

 Society, in addition to its own ' Proceedings,' shows, as did the 

 publication of Prof. Everett's O.Gr.S. system of physical data, that 

 the energies of the Society are well directed. It is to be hoped 

 that the scattered memoirs of many another physicist may be col- 

 lected and published by the same means. 



XXX. Intelligence and Miscellaneous Articles. 



THE ACTION OF MAGNETISM IN MOTION ON STATIC ELECTRICITY; 



INERTIA OF STATIC ELECTRICITY. BY G. LIPPMANN. 

 TT is known that previously to (Ersted's experiment it was in vain 

 ■*- attempted to connect magnetism with static electricity. Now- 

 a-days we can be certain that such a relation really exists, and we 

 can formulate the law of it even before making the experiment. A 

 magnet in motion exerts at a distance a mechanical action upon a 

 body at rest charged with free electricity. This action strictly 

 results from the existence of the inverse phenomenon, which has 

 been established by the experiments of Mr. Eowland*. 



It will be remembered that Eowland showed experimentally that 

 the motion of an electrized body acts on the magnetized needle as 

 a current would : the direction of the action changes with the sign 

 of the electric charge ; and the action due to a given displacement 

 of electricity is the same as if that displacement had taken place 

 under the form of a current properly so called. Such are the results 

 obtained by Mr. Eowland. On this ground I say that Mr. Eow- 

 land's phenomenon is necessarily reversible, and that its reversi- 

 bility is a consequence of the impossibility of perpetual motion. 



In fact, if we displace an electrized body so that each point in it 

 describes a closed trajectory n times, resuming every time the same 

 velocity at the same point, a magnetized needle near :t is submitted 

 during the movement to periodically variable forces, in virtue of 

 Eowland's effect ; this needle can therefore move under the action 

 of those forces, and furnish a quantity of work which differs from 



* Helmholtz, Berl. Berieht. 187G {Journal de Ffa/s. t. vi. p. 29) ; Phil. 

 Mag. [5] vol. ii. p. 233. 



