3 o8 
THOMPSON YATES LABORATORIES REPORT 
In this table are collected the results of twenty-eight experiments in which should 
be found data sufficient to test any presumed relationship existing between the effects 
of immersing the nerve in different concentrations of the same electrolyte, and also 
of different electrolytes. The immersions have been in solutions of seven electrolytes, 
all chlorides — 
Hydrochloric acid, 
Ammonium chloride, 
Lithium chloride, 
Calcium chloride, 
Barium chloride, 
Sodium chloride, 
Potassium chloride. 
It is of interest to commence with an examination of the relationship which we 
preliminarily tested, namely, a variation inversely as the concentration : and also 
with solutions of hydrochloric acid, for in their case the real relationship, as will 
subsequently be seen, is most obvious and convincing. 
The concentration of hydrochloric acid made use of are evidently capable of 
producing a wide range of effects. Solutions of -025 and -013 grammes per cent, 
produce, and in the right relative degree, the typical effects of dilute solutions, 
increasing the injury current. Solutions of ■ 1 and "2 per cent, produce the typical 
effects of concentrated solutions, diminishing the injury current, and also in the right 
relative degree. If in addition to this conformity to the general statement, they also 
conform to the assumed arithmetical relation ; then the value of 'x' in each of the 
following cases should be the same : ; — 
Experiment I — x = '2 x -31 = -62 
Experiment II — x = w x '62 = -62 
Experiment III — x = -025 x vz\ = '30 
Experiment IV — x = -0125 x 1*51 = '19 
In the first two of these experiments the value for ' x ' is the same, and there- 
fore, for these two cases, and presumably for intervening examples, it might 
be said that the potential difference varies inversely with the strength of the 
experimental solution. But when we turn to the remaining experiments (III and 
IV) we find that such a relation no longer exists, as is also the case with similar 
solutions of NaCl, i.e., those which also cause an increase in the value of the injury 
current. 
Faced with such a fact, it is natural to enquire the reason which induced us to 
seek for, and to appreciate when found, the existence of this inverse relationship of 
the value of the injury current to that of the experimental solution. The reason 
