282 M. G. Quincke on Electrolysis, and the 



which has been proved by numerous measurements by Faraday*, 

 Bufff. Soretf, Hittorf§, and others. And I have convinced 

 myself of this by experiments with watery solutions of blue 

 vitriol, which at different degrees of concentration and very dif- 

 ferent densities of the current confirmed the law to within 0*8 

 per cent, of exactness. 



With respect to the proportion of the quantities of salt decom- 

 posed simultaneously, Hittorf|| found that, with an aqueous 

 solution of iodide of potassium and chloride of potassium, the 

 proportion of the quantities of chlorine and iodine was not altered 

 when an electrical current was passed through the liquid for a 

 long time and the density of the current varied in the ratio of 

 1 : 3 or 1 : 4. 



The current passed through a liquid which contained an equal 

 number of equivalents of iodide of potassium and chloride of 

 potassium, also liberated an equal number of equivalents of 

 iodine and chlorine; in an aqueous solution of 3*157 equivalents 

 of KCl and 1 equiv. of KI, 3*157 equivs. of CI to 1 equiv. of I 

 were liberated by the same current. The partial conductivities 

 of KCl and KI appear from this to stand, in the same solution, 



in the ratio of the number of equivalents ( — j which are con- 

 tained in the unit of volume of the solution ; hence 

 C,e,-C',6', = C,e,-CV.. 



As, however, all the constants in this equation may change 

 with the nature of all the substances contained in the liquid, it 

 do^s not at once follow from this, as Hittorf conjectured, that 

 the resistance of a solution of KI is equal to the resistance of a 

 solution of KCl when both contain the same number of equiva- 

 lents in the same volume, although other experiments made this 

 relation probable^. But the above expressions accord with his 

 view that the resistance of the electrolytes stands in no kind of 

 relation to the chemical affinity of their ions as soon as a decom- 

 position of the corresponding chemical combination takes place. 



Also, in conformity with the above expressions, from a mix- 



^ Experimental Researches^ 387 &c. 



+ Liebig's Annalen, vol. Ixxxv. p. 1 (1853); vol. xcvi. p. 269 (1855) ; 

 vol. ex. p. 284 (1855). 



X Ann. de Chim. (3) vol. xlii. p. 257 (1854). 



§ Pogg. Ann. vol. Ixxxix. p.* 177 (1853); vol. xcviii. p. 1 (1856); 

 vol. ciii. p. 1 (1858) ; vol. cvi. pp. 337 & 518 (1859). 



II Pogg. Ann. vol. ciii. p. 50 (1858). 



II It is surprising, for instance, that under similar conditions IP SOS 

 HNO^ HCl dissolved in water show nearly the same conductivity, about 

 one 13,000th part of that of mercury (at 20°); likewise MgSOS ZnSO*, 

 CuSO^ about one 20,000th part, and so on. 



