THE ACTION OF SOLUTIONS OF ELECTROLYTES 
Preliminary Experiments Deciding the Choice of a Convenient Duration 
and Temperature for Immersion of the Nerve 
Three statements previously made are here repeated : — 
(1) That the 'core model ' structure of nerve is a fact and demands at least 
the presence of — 
(a) An external solution, 
(/;) A diffusion obstacle, 
(7) An internal solution. 
(2) That probably the internal solution is the more concentrated of the 
two, that at least the two are certainly different. 
(3) That the injury current is the inevitable outcome of such a set of 
conditions. 
These three statements are repeated because, with them in view, it is possible to 
intelligently follow all the modifications produced in the value of the injury current 
of nerve by the action of solutions of electrolytes. Thus granted that the value of 
this current (more strictly of the P.D.) depends upon the ratio existing between the 
concentrations of the two solutions, it at once follows that a replacement of the outer 
solution by a still more dilute solution should increase this value, and that replace- 
ment by a more concentrated solution should diminish it. It will be seen that this 
apparently antagonistic action between more dilute and more concentrated solutions 
has been found in the case of solutions of several electrolytes, it may be said in every 
such case in which it has been sought. 
There is, in tact, however, no real antagonism between the action of dilute and 
concentrated solutions of electrolytes. There is an apparent antagonism, because an 
arbitrary standard is chosen for comparison, namely, the concentration of the external 
solution already present upon the nerve when removed from the body. All 
appearance of paradoxical action is at once removed by the acceptance of water as a 
zero of concentration. 
The action of water was studied in the last section ; it is now our intention to 
study this action diminished by the addition of electrolytes to the water used, and it 
will be seen that the diminution increases with the quantity of electrolytes which is 
added. 
