Theory of Electrolytic Dissociation. 159 



Cadmium iodide, ammonium sulphocyanate, and sodium 

 iodide did not give normal molecidar weights at any of the 

 dilutions used. The molecular weights found for cadmium 

 iodide and ammonium sulphocyanate were larger than the 

 normal molecular weights for all the dilutions that were 

 employed ; while the molecular weights found for sodium 

 iodide were smaller than the normal for all the dilutions 

 studied. 



Another important point is that the molecidar weights of all 

 three substances changed with the dilution of the solutions, 

 becoming less and less as the dilution increased. 



On account of the small solubility of lithium chloride in 

 acetone, it could not be successfully studied. All three of 

 the above substances give very considerable conductivity in 

 acetone, showing that a large number of the molecules are 

 broken down into ions. 



Mercuric chloride in acetone gives molecular weights that 

 are very nearly normal, and these do not change appreciably 

 with change in the dilution of the solutions. But mercuric 

 chloride in acetone shoics practically no conductivity. At a 

 dilution of 36 litres the molecular conductivity is less 

 than unity, being only 0*734 according to the work of 

 Laszczynski*. 



I concluded my paper with the following statement f : — 

 " These substances instead of presenting any exception to the 

 theory of electrolytic dissociation fall directly in line with 

 the theory, as so many similar cases have done. Indeed, it 

 is extremely interesting to see how many apparent exceptions 

 to the theory of electrolytic dissociation disappear as experi- 

 mental methods become more refined and experimental work 

 more accurately carried out. The amount of evidence for 

 the general correctness of this most fruitful generalization is 

 at present so large that any apparent exception will be ac- 

 cepted only after it has been very thoroughly substantiated 

 by repeated experiments." 



Notwithstanding these facts and the conclusions drawn 

 from them, L. Kahlenberg states that "The facts presented 

 in the paper cited have since been corroborated by .... 

 H. (J. Jones and co-workers in their molecular weight deter- 

 minations on solutions." 



The sole object of these lines is to correct the above state- 

 ment made by L. Kahlenberg. 



Johns Hopkins University, 

 March 1905. 



* Ztschr. Electro-Chemie, ii. p. 56. 



t Amer. Chem, Journ, xxvii. p. 22 (1902). 



