280 M. G. Quincke on Electrolysis^ and the 



This is the more remarkable because it holds for a great 

 series of combinations in which the liberated partial molecules, 

 according to modern theoretical views, may be univalent or plu- 

 rivalent. On account of the difficulty of separating the direct 

 action of the electrical current from the secondary of the libe- 

 rated substances, we shall not for the present be able to decide 

 with certainty whether the electrical current only splits up the 

 total molecules, as appears to be mostly the case, into partial 

 molecules of an equal number of units of affinity (compare § 55). 



The aforesaid relations will not hold when a salt is dissolved 

 in water, alcohol, or the like. 



§65. 



Equation (24) § 55 gives the dependence of the specific con- 

 ductivity of a liquid on the constants C,., e,.ji?rj &c. Since as 

 good as nothing is known of these quantities, only the known 

 facts regarding the conductivity of the electrolytes can in general 

 be compared with that expression. 



The conductivity increases with the concentration of the solu- 

 tion of salt, with p, and with the heating, because through the 

 latter the constants C, C become greater and the particles more 

 easily displaceable. If the concentration increases too much, so 

 that by this means C, C decrease more quickly than p increases, 

 then the maximum of conductivity for a definite concentration 

 will be reached. 



All this is in accordance with experiment. Thus Hankel* 

 found that saturated viscous solutions of salt at once conducted 

 far better when by heating they were deprived of this viscosity. 

 Wiedemann t afterwards showed that for diluted watery solu- 

 tions of CuS04, Cu2N03,AgN0^ IPS04, KHO, NH^NO^ 

 the specific resistance is directly proportional to the viscosity of 

 the liquid, and inversely to the quantity of salt it contains. 



BeetzJ has examined very accurately the conductivity of solu- 

 tion of sulphate of zinc, and has found that in all concentrations 

 the conductivity increases as the temperature rises — most of all 

 near 0°, then more slowly. With a definite concentration the 

 maximum of conductivity occurs. Schmidt § found it was the 

 same for common salt, PaaJzow || and Kohlrausch and Nippoldt*[f 

 for sulphuric acid dissolved in water. 



* Pogg. Ann. vol. Ixix. p. 263 (1846). 



t Ibid. vol. xcix. p. 231 (1856). Wiedemann, Galvanismus, vol. i. 

 p. 425. 



t Pogg. Ann. vol. cxvii. p. 17 (1862). 



§ Ibid. vol. cvii. p. 556 (1859). 



II Berl. Monatsher. 1868, p. 4.90. 



IF Fogg. Ann. vol. cxvixxii. p. 385 (1869). 



