334 
THOMPSON YATES LABORATORIES REPORT 
Nor is this the most severe way in which the difference between anticipation and 
reality could be described. An examination of the first of these two tables will show 
that in this series of experiments the anticipated result was not even once approached ; 
that in the second table the anticipated result was only once obtained, and then in an 
experiment upon a ' second nerve ' (Experiment CLXXVII). The universality of 
the general ' concentration law ' has, therefore, broken down, while still the general 
statements made as to the graduated effects of solutions of different concentration 
are unaffected, as will be seen from the collection of the results in the following 
table : — 
« 
Solutions of Potassium Chloride 
Concentration in 
grammes per 
cent. 
Number of 
Sciatic Nerves 
examined 
Average initial 
Potential Difference 
Average final 
Potential Difference 
The Final Value 
expressed in terms of 
the Initial Value 
as unity 
7'45 
IO 
0160 Daniell 
■0018 Daniell 
o- 1 I 
372 
1 0 
•0174 
•0076 ,, 
°'44 
i-86 
I I 
•017+ 
■0105 
o - 6o 
'■+9 
8 
•0)8 1 „ 
•0123 
o-68 
075 
20 
•0175 
■0179 
ro2 
°'37 
20 
•0180 ,, 
■0190 
1 06 
o- 1 9 
20 
•0181 ,, 
0217 
1-20 
It has been pointed out (p. 325) that the ' concentration law ' has an interest of 
much greater magnitude than that given to it by the fact, that it successfully describes 
the effects of solutions within a wide range of concentrations. 
It has a value which is given to it by its own form. The form is, in the first place, 
a confirmation of the position which has been maintained in this paper as regards the 
method of production of the injury current. In the second place, the actual numerical 
values of the expressions contained in this law have a very great interest ; for no 
matter what the explanation of the quantitative relation discovered between the results 
of immersion in solutions of varied concentration, whether it is the one here taken or 
some other, the expression Ea = Eft> log. - gives rise intrinsically to a most im- 
portant question. 
This expression {since log. 1 = o) predicts a value for the solution, an immersion in 
which should reduce the value of the injury current to zero ; and the prediction is a very 
