CHEMISTRY: WASHBURN AND MILLARD 
145 
extent than is the chloride-ion. Moreover, a quantitative relation be- 
tween the number of mols of water iY^ on the cesium ion and the num- 
ber on the chloride ion can be derived from these results, as follows: 
iVS' = 0.67 + 1.03iVS^ 
For the purpose of comparison the corresponding relations previously 
obtained for the three other alkali chlorides^ and for hydrochloric acid^ 
at 25° at about 1.2 molal are here brought together with those for cesium 
chloride. The iV^'s indicate the average number of water molecules 
carried by the ion indicated by the superscript as it moves through the 
solution. The values given are the means of the two results obtained 
at the two electrodes independently. The deviation of this mean from 
the two individual values is indicated in each instance by the term pre- 
ceded by the ± sign. 
=0.28i0.04+0.185A^S^ (1) 
Nl' = Q.61±0A 4-1.03 N^^ (2) 
A^^ = 1.3 ±0.2 +1.02 N^^ (3) 
iV^^=2.0 ±0.2 -1-1.61 N^^ (4) 
iV^^ = 4.7 ±0.4 4-2.29 N^^ (5) 
From equations (2) and (3) we get the relation N^ — N^ = 0.65, 
which shows that the cesium ion carries on the average 0.65 less molecules 
of water than the potassium ion and is therefore the least hydrated of 
the alkali ions. 
From equations (1) to (5) it follows, if we assume that the chloride 
ion is unhydrated, that the numbers of mols of water carried by the 
other ions are : 
H+ 0.3; Cs+ 0.7; K+ 1.3; Na+ 2.0; Li+ 4.7. 
If we assume that the chloride-ion contains 4 mols of water, then the 
numbers contained in the other ions are : 
H+ 1.0; Cs+ 4.7; K+ 5.4; Na+ 8.4; Li+ 14. 
Some experiments were also made with potassium nitrate; and, al- 
though the results were not quantitative, it was definitely shown that 
the water moved from the anode to the cathode in the case of this salt 
also. 
All of the results given above are based upon the assumption that the 
rafhnose remains stationary during the passage of the current. There 
is thus far no evidence indicating that this assumption is invalid to an 
