264 



equilibrium. Tiiis is the reason why the so-called super-tension of 

 hydrogen is different, when different metal cathodes are used. 



It is self-evident liiat when the state of formation of the hydrogen 

 does not vanish too quickly, tiie i)ydrogen must possess an almormallj 

 high conductivity for electricity immediately after the escape. This 

 phenomenon was, indeed, found long ago'), but it was tried to 

 explain it in another way ; it is, however, probable that this phe- 

 nomenon is for the greater part to be attributed to the slate 

 of formation. 



The activity of the hydrogen dissolved in the metal phase, is in 

 perfect harmony with the considerations given here. As regards the 

 temperory variations of the super-tension, tiiey will have to be 

 explained by the slow change in constitution of the coexisting 

 phases. The heterogeneous equilibrium between the boundary layers 

 is established with great velocity, but the composition of the phases 

 changes slowly, and this must be the reason that the three-phase 

 equilibrium metal-electrolyte-hydrogen changes slowly. 



In conclusion I will still |)oint out that analogous considerations, 

 of course, apply to oxygen and other non-metals. As is discussed 

 in "The Theory of Allotropy" p. 160 et seq, the extension of 

 this theory to non-metals, necessitated the assumption that the atoms 

 of all elements can split off and receive electrons.') The difference 

 between the solubilities of the positive and the negative ions in 

 elements with pronounced metal- resp. metalloid character, is so 

 great that for the explanation of the electro-motive behaviour as a 

 rule only the positive or the negative ions need be taken into 

 account. But as was also already stated the supposition mentioned 

 must very certainly be used when the positive charges of non-metals 

 with regard to electrolytes, and likewise the small electric conducti- 

 vity of non-metals in electrically neutral condition, is to be explained. 

 Further the said supposition is also required to make clear the 

 formation of compounds between metals.') 



When we now return to the non-metals and choose oxygen as 

 example, we have to consider the two following reactions : 



0,^20"'- 4- 2r, /9 

 and 



0, + 2r, (9^20"'" 

 As v, = 2, the latter reaction may be written : 



0, + ie:;t20". 



') BscKER. Jahrb. der Radioaktivitat. 9, 52 (1912). 

 ») Theory of Allotropy p. 160. 



