666 Proceedings of the Royal Society of Edinburgh. [Sess. 
therefore be assumed in calculation that the speed of the ions is 
normal. 
Another possibility which was considered was that the ionising power 
of the water might be altered in presence of the strong electrolytes in the 
solution. 
To test this supposition, the conductivity of a series of solutions of 
hydrochloric acid diluted with 
N 
8 
acetic acid was compared with the con- 
ductivity of a series diluted with water. With the same object, solutions 
of KC1 were diluted with water and NH 4 OH, and solutions of NaCl with 
water and dimethylamine, respectively, and the conductivity of the resulting 
solutions taken. The pairs of substances were chosen with positive ions of 
as nearly as possible the same speed, so that double decomposition alone 
would not affect the conductivity. 
I. — 24*9° C. Conductivity of Hydrochloric Acid, diluted with — 
V. 
(1) Water. 
(2) — Acetic Acid. 
v ' 8 
16 
391-7 
392-3 
387-4 
389-3 
32 
401 
399-2 
398-5 
397-8 
64 
407-7 
405-8 
403-4 
404-8 
128 
413-6 
412-2 
410-6 
410-1 
Molecular conductivity of the acetic acid = 4'65. 
IT. — 25° C. — Potassium Chloride diluted to — with — 
8 16 
(1) Water. (2) - NH 4 OH. 
8 
fi = 131-6. 135-2. 
N N 
III.—— Sodium Chloride diluted to — with — 
8 16 
(1) Water. (2) Dimethylamine ’0578 N. 
110-2. 131-5. 
Molecular conductivity of the dimethylamine = 21. 
In every case we see the resulting conductivity to be just what would 
be expected from the ordinary dissociation theory, so that no abnormality 
need be looked for in this respect. 
We are forced to conclude that there are fewer molecules in the 
solution of the salt of an amphoteric electrolyte than there would be in the 
