THE INJURY CURRENT OF NERVE 
335 
remarkable one. For the value of the predicted concentration is one gramme 
equivalent molecule (dissociated) per litre, and is, therefore, very great ; being that 
of a solution capable of exerting an osmotic pressure ten times greater than that of 
ordinary ' normal saline ' solution. 
If, therefore, the theory here maintained is the true one, if the injury current is 
due to the contrast between internal and external solution, if also the electrolytes of 
this internal solution are not very different from the chlorides examined ; then the 
concentration law, as found, points to the existence of a solution of this extraordinary 
concentration within the axis cylinders of the nerve fibres. 
If on the other hand, the theory now maintained and supported by so much 
circumstantial evidence is false ; then, if still the ' concentration law ' holds good, an 
explanation has to be found for this relationship explanatory of another indication which it 
holds forth, namely, that a solution of greater concentration still must reverse the direction of 
the injury current. 
k 
For take the expression Eo, = Ea log - ; in this expression when ' n ' is greater 
than ' k,' then log - becomes negative, and with it necessarily also the value of E^, 
the final potential difference after immersion. 
In illustration of this necessity the following experiments with solutions ot 
NaOH are given. The data given are the results of experiments upon sciatic nerves 
(cats) exactly similar to the preceding ones, and like them shewing the effect ot 
immersions of five minutes duration. 
Solutions of NaOH 
Number of Experiment 
Concentration of 
the Solution in 
grammes per 
cent. 
Initial Potential 
Difference 
x 10 — 3 Daniell 
Final Potential 
Difference 
x 10— 3 Daniell 
Final Value 
expressed in terms 
of the Initial 
Value as unity 
(I) •■• 
0 - 02 5 
23 - 0 
+ 23-9 
+ I '04 
Experiment CLXXX (2) ... 
0-063 
+ 20' I 
+ i-6o 
CLXXXI (i) ... 
OT 2 5 
132 
+ 15-0 
+ I-I4 
(i) ... 
0-250 
20- I 
+ 9 - o 
+ 0-45 
CLXXXII (i) ... 
0-500 
20"9 
+ 1-9 
+ 0-09 
CLXXXIII (2) ... 
rooo j 
20-3 \ 
" r3 1 
— o - o6 \ 
CLXXXIV (i) ... 
1 -ooo ) 1 
I3-3 ' 
- r 3 J 
— 3- 16 / 
* Experiments previously quoted on pages 298, 301 
