ee? i gee a ee 
1016 
I have tested this assumption, using the conductivity method, and have — 
obtained the following results : 
“, = molecular conductivity at dilution vy, 
vy = number of liters in which one gram molecule of substance is 
dissolved. 
C = constant of the conductivity cell used. 
w = resistance in ohms of the rheostat. 
a and b = the lengths in millimeters on the measuring arm of the Wheat- 
stone bridge. 
Lak a 
mere whence 100a—dissociation expressed in per cent. 
2 
k = affinity constant of the base = - *" for a weak base. 
v(1-a) 
The calculations are based on the usual formula: «#, = > C. All measurements 
were made at 25°, 
Echitamine hydrochloride. 
Vv Mey, 
42 84.5 
168 85.5 
420 87.5 
Echitammonium hydroxide. 
Vv My, 1004 k 
35 57.7 27.6 . 0030 
140 58. 7 28 . 00077 
350 65.5 31.3 . 00036 
co 209 
If echitammonium chloride is assumed to be completely dissociated at 
the dilution v=420, the molecular conductivity of the chlorine ion is 
taken as 75 for that dilution, and the molecular conductivity of the 
hydroxyl ion at dilution co is taken as 196, then 13 results as the molec- 
ular conductivity of the echitammonium ion and 209 as the molecular 
conductivity of echitammonium hydroxide at infinite dilution. From 
these results it is seen that it is too strong a base for its affinity constant 
to be calculated by the dilution formula given above, which is accurate 
only for weak bases and acids, but, as it is dissociated in a 1 per cent 
solution to the extent of about 28 per cent, it is moderately strong. 
For purposes of comparison I add the figures obtained by Bredig *® 
on coniine and piperidine, and also measurements made by myself on 
atropine. 
° Ztschr. f. physik. Chem. (1894), 13, 289. 
