﻿Constitution of Aqueous Solutions. 5 



The striking result in this Table is that r— 1*29 +.v for all 

 the positive ions has a positive sign and r — l"29+y for all 

 the negative a negative. Most probably then the same 

 phenomenon holds in regard to t. If so, then, so far as I 

 know, this is the first case in molecular physics where, apart 

 from purely electrical considerations, the opposite charges of 

 the two sorts of ions are known to manifest themselves by 

 opposite actions. Positive ions decompose (H 2 0) 3 into (H 2 0) 2 , 

 while negative ions form (H 2 3 ) out of (H 2 0) 2 . 



As regards the — l'29 + .v and — 1'29+y which associate 

 with t, the problem is to find % and y. I have been able 

 only to guess at a solution by the following train of thought. 

 Since r — 1*29 4- y has for CI a negative value numerically 

 much greater than the positive values for Li, Na, or K, it 

 appears probable that 1*29 belongs almost wholly to the 

 positive ions, and hardly at all to the negative. Tentatively 

 then I have added 1'29 to t— 1'29 + d- as given for the 

 positive ions, and to t— 1'29+y as given for the negative ; 

 and I have tabulated the results in Table I. as t; that is 

 to say, I have arbitrarily put # = 0, y = l*29, a procedure to 

 be justified by the results to which it leads in the next section. 

 But altogether apart from this, the table supplies independent 

 confirmation of the hypothesis of electrolytic dissociation in 

 aqueous solutions. 



2. Theory of Density. 



From the values of t in Table I. it appears that, with the 

 exception of C0 3 , an equivalent of an ion unmakes or makes 

 from 1 to 2*5 molecules of (H 2 0) 3 . This seems to indicate 

 that an ion controls the structure of only those molecules of 

 water which are in its immediate neighbourhood. So we are 

 constrained to form a theory to account for the novel type of 

 dissociation here presented with its manifest bearings on 

 catalytic actions and the coagulation of colloids. The electron 

 formula proposed for (H 2 0) 3 in "Ionization, Ionic Velo- 

 cities, and Atomic Sizes n (Phil. Mag. [6] iii. p. 162) assumes 

 tetrad valency for the atom due to 6 negative electrons \y 

 and one positive Jf. The binding of the three atoms in 

 (H 2 0) 3 may be represented thus, with the letter A to denote 

 one of the three effective bonds §\) : — 



OfAbO 



b % 

 So* 



