THE INJURY CURRENT OF NERVE 
3 2 5 
The approximation is sufficiently close to point to a very definite moral ; namely, 
that the actions or all these solutions are in very definite agreement, and depend 
upon a property common to them all. 
The property can also be assigned definitely as attributable to the dissociated 
moiety of these electrolytes, to the electrically charged ions contained in these 
solutions ; since it is obviously dependent upon the number of ions present. 
Further, there remains the remarkable fact, not yet commented upon, that the 
form of the law determines one concentration which should reduce the potential 
difference to zero : and that this particular concentration, since log. i = o, is n = r. 
A solution of concentration n = i, one equivalent gramme molecule per litre 
of dissociated electrolyte should cause the injury current to vanish. Such a necessity 
logically carries us to an extraordinary conclusion, when attention is paid to the main 
contention which we have attempted to establish : namely, that the current of injury 
is due to the inequality between the ' external ' and ' internal ' solution of the nerve. 
For equality of these two solutions is the condition essential to the elimination of the 
injury current; and it must be admitted that, with the figure just given, equality is 
reached at an extraordinary concentration of the ' external solution.' 
Such a conclusion necessitates a very rigid examination of the ' concentration 
law,' and this seems best performed by an exhaustive examination of the action of one 
of those electrolytes over a wide range of concentration. 
There does not seem to be any great advantage obtainable from the choice of a 
special electrolyte, the action of all so far being similar. For this examination KC1 
has been chosen thus at random. 
