THE PHYSICAL PROPERTIES OF AQUEOUS SOLUTIONS. 
119 
It will be seen that whilst the ordinary values of a widely diverge at a concentration 
of twice decmormal, the corrected values of « are nearly the same. Beyond this point 
the values diverge. # 
Table IX.—Values of a. 
X 
a ~ A 
7/7. 
1 
KC1. 
NaCl. 
Difference. 
0-0001 
0-9921 
0-9918 
O 
O 
0-0002 
0-9898 
0-9893 
5 
0-0005 
0-9847 
0•9834 
13 
o-ooi 
0-9788 
0-9771 
17 
0-002 
0-9709 
0-9684 
25 
0-005 
0-9563 
0-9522 
41 
0-01 
0-9411 
0-9354 
57 
0-02 
0-9221 
0-9140 
81 
0-05 
0-8897 
0-8782 
115 
0-1 
0-8611 
0-8424 
187 
0' 2 
0-8298 
0-8049 
249 
a = 
X 
A 1 + ffi 
KC1. 
NaCl. 
Difference. 
0-9916 
0-9890 
0-9833 
0-9765 
0-9673 
0-9499 
0-9311 
0•9065 
0-8622 
0-8194 
0-7687 
0-9981 
0-9893 
0-9833 
0-9765 
0-9672 
0-9495 
0-9309 
0-9064 
0-8632 
0-8189 
0-7680 
— o 
+ 
± 
+ 1 
+ 4 
+ 2 
+ 1 
- 10 
+ 5 
+ 7 
A greater divergence in more concentrated solutions is to be expected, and it is 
important to point out the reason therefor. 
(-) Distinction between Autolytes and Heterohjtes.—ln a recent paper (Bousfield 
and Lowry, ‘Phil. Trans.,’ A, vol. 204, p. 256, 1905) attention was drawn to the 
difference between autolytic and heterolytic conductivity,! and it was shown that 
an electrolyte, such as sodium hydroxide, which was a good conductor in the melted 
state, showed clear indications of autolytic conductivity in the more concentrated 
solutions. It may be supposed that, as in dilute solution, water combination is the 
effective force producing ionisation, so in the melted state self-ionisation (resulting in 
autolytic conduction) is produced by the combination of the ions with molecules of the 
melted salt. . In concentrated solution, this action probably still persists, and though 
we have mainly heterolytic ionisation produced by combination of ions with the 
solvent, we may have also some autolytic ionisation produced by combination of the 
ions with molecules of the solute.* KOI and NaCl belong to the class of autolytes, 
Since this paper was communicated, I have made an examination of a group of nine salts with reference 
to this matter, and have come to the conclusion that no stress should be laid upon the near approach to 
equality of the values ot « for KC1 and NaCl. If water combination be the efficient cause of ionisation, 
one would expect that the great differences in the amount of water combination with different salts 
would lead to corresponding differences in the values of a. This turns out to be probably the case. 
t These words were adopted by Dr. Lowry and myself at the suggestion of Professor Armstrong, 
to indicate the phenomena to which, attention was called. 
* This fcl ^ eoi T has been recently developed In a paper by Dr. LowrY,* ‘ Trans. Faraday Society,’ vol. 1, 
1905, p. 197, " An Application to Electrolytes of the Hydrate Theory of Solutions,” 
