11 
The theoretical results at which we have arrived may be 
tabulated as below : — 
State of 
Nature of Re-agent, 
Organism. 
Kation faster 
than Anion, 
Anion faster 
than Kation. 
Oalvanotaxis. 
Positive 
Negative 
Isotactic 
Attraction 
Repulsion 
Attraction 
Repulsion 
Attraction 
Attraction 
Attraction to Kathode 
Attraction to Anode 
Attraction t(j Anode 
and Kathode 
The stimulation effect of a re-agent will be proportional 
to the difference of potential between the organism and the 
u V 
medium. This will be =k 
Vi 
— log. -^. Where k is a constant 
U + V e Cj 
(the temperature being constant), u and v are the velocities 
of the kation and anion respectively, i/i ^^^ ?/o are 
their valencys respectively, and c^ and c^ are the con- 
centi'ations of the electrolyte in the medium and in the 
organism respectively.* If — be constant, and it is pro- 
bably nearly so when equivalent solutions are used throughout, 
we have that the stimulation effect of an electrolyte is propor- 
u V 
tional to 2/i ^2, which we may call the "stimulation 
w + V 
efficiency " of the electrolyte.! Since 
is Hittorf's 
u + V 
transport number," and is usually denoted by n , the stimu- 
1-n 
lation efficiency may also be expressed bv - — , which 
. . . ^ 2/i 2/2 
reduces to 1 - 277, if the ions are mono-valent. 
We cannot assume, it is true, that the stimulation effects 
of different re-agents will be strictly proportional to their 
*Vide Whetham : A Treatise oiQ the Theory of Solution, 
1902, page 382. 
t I originally defined the ''stimulation efficiency" as -^ 
>' + V 
which, of ooui-se, is only true for univalent ions. I am indebted 
to Mr. J. A. Craw for the above correction. 
