ON ELECTROLYSIS IN ITS PHYSICAL AND CHEMICAL BEARINGS. 341 



Professor Kohlrausch has favoured the Committee with the folloiuing letter 

 (in English) addressed to the Editor. 



Wurzhurg, January 6, 1887. 



My dear Coll eagtje,— You have had the kindness to send me a proof of part 

 of the Eeport on Electrolysis before finally going to press, and I must take advan- 

 tage of your friendly permission to express my own views on the subject. 



Since I consider it of great importance not to be misjudged in the reports of so 

 prominent a body as the British Association, I caimot avoid making a personal 

 remark. M. Bouty writes that the aim of my last published memoir was ' to 

 control the results of the experunents of Messrs. Lenz, Ostwald, Vincentini and my 

 (Bouty's) experiments of 1884.' ' M. Bouty is mistaken, certainly with all good 

 intention, as to the course of my research. I already in 1874 carried on a series 

 of experiments with diluted solutions. Allow me to give, as a proof of the perfect 

 independence of my research, a series of observations on sulphuric acid, made on 

 January 30, 1875. 



Per cent. HSO, p= 5-05 1-03 -339 '0992 -0324 -0098 -00.306 -00099 



Conductivity 



at 18° kl08 = 19S5 443 1645 55-1 20-45 6-77 2-06 0-57 

 108 •'/p= 393 430 479 656 631 690 673 580 



Nitric acid (February, 1875) 



Per cent. HNOg p = 6-32 2-05 -512 -100 -0152 



Conductivity 



at 18° kl08^ 2970 1045 275 55-8 8-65 

 108 ''/p= 470 510 537 658 570 



These numbers have been written for more than ten years in my books. The same 

 ^ve, when calculated in reference to the molecular number m : — 



Sulphuric acid 



m = l-06 0-212 0-0698 0-0202 0-00661 -00200 -000623 "000202 

 106 kj_^ = 187 -Aid 233 273 309 340 331 280 



m = l-04 0-328 0-0813 0-0159 0-0024 

 .10«''/m=28B 319 338 352 360 



The molecular conductivity ''/,„ of the sulphuric acid increases very rapidly by 

 greater dilution, and very nearly reaches that of nitric acid. Extreme dilution 

 causes again a decrease. This is the chief part of that research ; it was published 

 nine years later by Ostwald and then by me. 



I discontinued these observations at that time, partly for the very reason that 

 they gave such new results. The initial increase of ''/p for sulphuric acid, and the 

 final decrease, made me suspicious ; besides, the observations at that time were 

 connected with difficulties, inasmuch as I could not so easily measure great 

 resistances ; also I could not obtain very pure water. At best the new object 

 demanded a thorough research, which would draw me too far from my chief object. 

 If one is working in an entirely new field he ought not to spend too much time on 

 particulars.^ 



That dilute solutions are of very great interest has been emphasised in the fu-st 

 memou- by Grotrian and myself (1874), and later often enough in my publications. 

 Indeed I limited myself then to combining those relations equally from the results 

 ■which alone at that time were at my disposal, i.e. solutions of moderate dilution. 



' p. 339. 



^ In order to protect myself against the reproach of a too one-sided investigation, 

 I would further remark that I early informed myself concerning mixtures of salts as 

 well as acids in aqueous solutions, also concerning salts in alcoholic solutions, and 

 finally, concerning mixtures of water and alcohol, many years before. After the 

 publication of detailed researches of other authors I ceased to continue these inves- 



D 



