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LI. On Helmholtz's Electrochemical Theory, and some 

 Conclusions deduced from the same. By F. Richakz. 



To the Editors of the Philosophical Magazine. 



Gentlemen, 



PROFESSOR G. Johnstone Stone y, in his paper on 

 the " Electron," or Atom of Electricity, in the Philo- 

 sophical Magazine of October 1894, very rightly draws 

 attention to the fact that he expressed himself first, with 

 regard to Faraday's law, at the Belfast Meeting of the 

 British Association in August 1874, as follows : — " For each 

 chemical bond which is ruptured within an electrolyte a 

 certain quantity of electricity traverses the electrolyte, which 

 is the same in all cases." 



Professor G. J. Stoney calls this smallest quantity of elec- 

 tricity the " Electron/' and estimates it at 3 x 10 -n of the 

 C.G.S. electrostatic unit of electricity. 



In this view, therefore, he anticipated Helmholtz in his 

 Faraday Lecture in April 1881. Helinholtz, however, then 

 propounded further the hypothesis that. " in the case also of 

 non-electrolytes, the ( Valencies ' are charged with the same 

 atoms of electricity." Helmholtz explains, moreover, the 

 grounds for the supposition that the attraction between the 

 electrons is the most essential and the greatest part of che- 

 mical force. The old electrochemical theory of Berzelius 

 acquired herewith an entirely new form through Helmholtz 

 in respect of the quantity of the atom charges, and deserves 

 therefore the title of " Helmholtz's Electro-chemical Theory." 



Without knowing Prof. G. Johnstone Stoney's calculation 

 of the " Electron," I also, in a paper " Ueber die electrischen 

 Krafte der Atome," read before the Niederrheinische Gesell- 

 schaft fur Naturkunde on the 1st Dec. 1890 and 12th Jan. 

 1891*, calculated the electron, and first attached thereto cal- 

 culations fitted to decide whether et the forces operating in 

 the atoms of a molecule have the same order of magnitude as 

 the electrostatic attraction of the valency-charges." 



That this is the case 1 had then already proved, in respect 

 to the dissociation heat N 2 4 into 2N0 2 , and I 2 into 21. 



I have further assumed that both atoms of a molecule 

 revolve round each other with a constant velocity, which is 

 given by Boltzinann's kinetic theory of polyatomic gases. 



* F. Richarz, Sitzungsberichte j Bonn, vol. xlvii. p. 113 (1890); 

 ,vq1. xlviii. p. 18(1891). 



