1 56 
MR. W. R. BOUSFIELD: IONIC SIZE IN RELATION TO 
I am 
O 
e factor necessary to obtain the equivalent conductivity, entirely swamps the small 
inference (if any) from the exact value of the index which we desire to detect. 
Hence the only available means of investigation is to get the true value of n at 
high dilutions, by extrapolation from lesser dilutions where the errors to which 
reference is made above become almost inappreciable. For this purpose a range of 
dilutions is chosen between normal and y^oo normal. As we descend through 
this range of dilutions (from higher to lower dilution) we necessarily get an increasing 
divergence from the true value of n, owing to changes of viscosity and changes of 
ionic size, but we can extrapolate into the desired region where viscosity and ionic 
size are nearly constant. 
According to the Van ’t Hoft law, in the modified form adopted in this paper, ii 
= log p—~> V — l°g —> we ought to have dyfdx = §. 
In the following tables are set out the values of a (uncorrected, that is to say 
x 
Table XXXII.—KC1. 
in. 
A 
a = A 
log h. 
i k 
y=l°g-. 
i h 
x = log - - 
1 — a 
a y. 
Ax 
A/ 2 
Ax 3 ‘ 
0-0005 
0-9847 
5-04477 
5-0515 
6-8601 
0-674 
0-007 
o-ooi 
0-9788 
4-74374 
4-7531 
6-4174 
0-678 
0-011 
0-002 
0-9709 
4-44270 
4-4555 
5-9788 
0-681 
0-014 
0-005 
0•9563 
4-04474 
4-0642 
5•4043 
0-683 
0-016 
0-01 
0-9411 
3-74367 
3-7700 
4-9736 
0-691 
0-024 
0-02 
0-9221 
3-44248 
3-4777 
4-5509 
0-697 
0-030 
0-05 
0-8897 
3-04419 
3-0950 
4-0016 
Table XXXIII.—NaCl. 
in. 
A 
log h. 
i h 
y = log — 
, h 
Ay 
Ay „ 
a - A' 
x log i~A 
Ax 
Ax h ' 
0-001 
0-9771 
4-74375 
4-7538 
6-3839 
0-674 
0-007 
0-002 
0-9684 
4-44271 
4-4566 
5-9430 
0-676 
0-009 
0 • 005 
0-9522 
4-04475 
4-0660 
5-3653 
0-679 
0-012 
o-oi 
0-9354 
3-74368 
3-7727 
4-9335 
0-684 
0-017 
0-02 
0-9140 
3-44259 
3-4816 
4-5081 
0-693 
0-026 
0-05 
0-8782 
3-04444 
3-1009 
3-9588 
