122 
MR. W. R. BOUSFIELR : IONIC SIZE IN RELATION TO 
independent of any hypothesis, is to take the relation in the form shown in 
equation (12), viz., 
n, = N 2 +N 2 (B 2 -B)(B+/a 23 )- 1 .(12), 
which gives n 2 as a linear function of (B + /?, 23 ) -1 , and to set out the values of n 2 as 
ordinates upon the values of (B + h 23 )~ 1 as abscissae. This is done in Diagrams II. 
and III. In the following tables are set out the values of the Hittorf numbers 
Table XI.—-Hittorf Numbers for KC1, calculated from the Radions. B = 3’33. 
m. 
m. 
(B+ **/»)-!. 
72-2* 
Difference. 
Observed. 
Calculated. 
o-oi 
313-2 
0-0031 
0-506 
0-506 
+ 
0-02 
197-2 
0-0050 
0-507 
0-506 3 
+ 0-7 
O'05 
107-0 
0-0090 
0-507 
0-507 
± 
o-i 
67-4 
0-0141 
0-508 
0-508 
+ 
0-2 
42-4 
0-0219 
0-509 
0-509 
+ 
0-5 
23-0 
0-0380 
0-513 
0-512 
+ 1 
1-0 
14-4 
0-0565 
0-514 
0-515 
-1 
Table XII.—Hittorf Numbers for NaCl, calculated from the Radions. B = 2 - 8. 
m. 
F 3 . 
(B + F 3 )- 1 . 
n 2 . 
Difference. 
Observed. 
Calculated. 
0-05 
107-1 
0-0091 
0-614 
0-614 
+ 
o-i 
67-4 
0-0142 
0-617 
0-616 
+ 1 
0-2 
42-4 
0-0221 
0-620 
0-620 
+ 
0-5 
23-0 
0-0387 
0-626 
0-627 
- 1 
1-0 
14-4 
0-0581 
0-637 
0-636 
+ 1 
according to Kohlrausch (‘ Leitvermogen der Elektrolyte,’ Ed. 1898, p. 201). There 
are also set out the values of h 23 calculated from the values of m given by Kohlrausch, 
and the values of (B + /t 2/3 ) -1 , taking, for KOI, B = 3'33 and, for NaCl, B = 2-8. There 
are also given the values of the Hittorf numbers calculated from the expressions 
for KC1. n 2 = 0-5055 + 0T6 (B + /t 2/3 )-\ 
and for NaCl .... n 2 = 0-610 + 0-45 (B + A 3 * 3 )" 1 . 
It will be seen that the agreement between observed and calculated values is very 
close. This linear relation is quite independent of the theory, but predicted by it, 
and therefore affords strong support to our hypothesis. 
