342 



Dr. Kohlrausch. The Resistance of the Ions [Feb. 17, 



(3.) Discussion of Results. — We may derive from the above fact the 

 certainty that the individual differences of the electrolytes come under 

 a common law, the degree of accuracy of which must, however, remain 

 unsettled. This law I have stated as follows : for dissociated aqueous 

 solutions the coefficient f$ of the quadratic member can be approxi- 

 mately expressed in terms of the coefficient a of the linear member, in 

 the form [3 = C (a - A), where C and A are constants common to all 

 electrolytes. One sees at once that this law is identical with the 

 other ; all curves of the expression (1 +cd + fit 2 ) pass through the same 

 point, having for its abscissa - 1/C* 



The proposed constants have the following values, taking 18° C. as 

 the point from which the temperature is reckoned, C = 0*0163, 

 A = 0'0174. The convergence takes place at the point where 

 f-lS = -1/0-0163 - -61, or t = -43°. On account of the small 

 difference between C and A, this point lies not far from the zero axis. 

 If C and A were identical, the extrapolation according to the quadratic 

 formula would show that the conductivity of all electrolytes becomes 

 zero at the same temperature. Introducing this critical temperature t Qi 

 all electrolytes could be nearly represented by a formula containing but 

 two individual constants, 



On the one hand, I consider it impossible that the inequality of A 

 and C, and the resulting deviations from a common point of converg- 

 ence on the zero axis are produced by errors of observation. Even 

 the circumstance that we have no completely dissociated solutions can 

 scarcely have so great an influence. On the other hand, it appears very 

 improbable that the approximate equality of the constants A and C 

 is purely accidental. The deduction that the extrapolated curves all 

 have a nearly common point of convergence appears to me especially 

 worthj 7- of notice in that this point lies approximately at the zero 

 value of the conductivity. The importance of this is still more 

 increased by the fact that if the mobility of the water particles be 

 extrapolated according to the same formula, it becomes zero at about 

 the same temperature (cf. 4). 



(4.) Variations of the Fluidity of Water with Temperature.— The relations 

 which have just been mentioned concerning the motions of the ions 

 in water assume a greater interest when they are compared with the 

 mobility of the water particles themselves. The fluidity (the reci- 

 procal of the viscosity) of water when calculated in the same way as 

 the conductivity, with the quadratic formula, is represented by the 

 lowest curve. 



That the best observations on the fluidity of water agree excellently 



* The coincidence in the drawing differs a little from this, because each cf the 

 expressions is multiplied by its corresponding A. 



