2 Messrs Carse and Laby, A relation between the velocity 
Ion of 
Va. 
Ion of 
Va. 
Ion of 
Va. 
Formic acid... 
17-9 
Ethyl amine 
21-3 
Aniline 
18-1 
Acetic „ ... 
15-7 
Allyl 
19-7 
Methyl aniline 
18-7 
Propionic ,, ... 
15-4 
Propyl 
19-6 
o-Toluidine 
17-8 
Butyric „ ... 
14-9 
Isopropyl „ 
19-8 
[p-Toluidine* . . . 
17-3J 
Isobutyric acid 
15-1 
Diethyl „ 
19-0 
?re-Toluidine — 
17-4 
n- Valeric ,, 
14-9 
Isobutyl ,, 
18-8 
Benzylamine. . . 
18-2 
w-Caproic ,, 
14-8 
Isoamyl ,, 
18-5 
Ethylaniline . . . 
17-1 
Dipropyl „ 
17-7 
Diethylaniline. 
17-3 
Pyridine 
21-4 
Triethyl „ 
18-8 
a-Picoline 
20-3 
Benzyl 
18-2 
* A solid. 
a— a Lutidine.. 
19-8 
Diisobutyl ,, 
16-7 
Ethyl pyridine 
20-0 
Tripropyl „ 
16-3 
a-Collidine 
19-7 
Ionic Volumes and Velocities. 
The velocities have been obtained from Bredig’s memoir * and 
converted into centimetres per second per volt per centimetre by 
multiplying his values by IT x 10 -5 . 
In finding the value of the cube root of the ionic volume a, the 
methods of the previous paper have been somewhat extended. 
The calculation of the ionic volumes can be best explained by 
means of the following examples : — 
(1) Volume of the cation, trimethyl-a-naphthyl-ammonium, 
CN (CH 3 ) 3 : CH 
6 4 ‘CH : CH 
or C 13 H 16 N. 
The molecular volume of 1-naphthylamine -5 
hydride, 
CHo . CHo . CH : CN H 2 : CH 1471 
CH 2 . CH 2 . CH . CH : CH ’ at b " _ 1062 
+ (C 3 H 7 )j, = 13 x 5'3 
: 6 : 7 : 8-tetra- 
= 138-6 
= 68-9 
207*5 
* 
— volume of 4 hydro H atoms = 16 - 0 
(C 13 H 16 N)» . =^91 -0 
cube root of (Ci 3 H 16 N)„ = 5 ‘76 
which is a for this ion. 
78 
Note — (C 6 H 6 )„ at 0°C. = 7 ^— „= 86 - 6 
(C«H„)„at = 110-7 
thus 6 hydro H atoms = 24T. 
* Zeit. f. Phys. Chem. xm, p. 191 (1894). 
