THE INJURY CURRENT OF NERVE 
34i 
succeed in this attempt it was considered necessary to deliberately dry the nerve, even at the 
apparent risk of" injuring it, until it no longer left any damp mark upon the filter paper. 
The minuteness of the alteration in weight recorded in experiments A and B is taken as 
evidence of this attempt. 
The point is not unimportant, since the fact which it establishes is of interest from the point 
of view that the external solution is a 'short circuiting solution.' The fact may be stated as 
follows : — 
The bulk of the pre-existent external solution, unlike its conductivity, was not affected in 
these experiments. 
From these data the ' specific resistance ' in each case can be calculated (for 
method see p. 260) and is — 
Before After 
186 ohms 190 ohms 
corresponding to a 'specific conductivity' in each case respectively of 50*7 and 50*2, 
expressed in the usual units. 
The alteration in the specific conductivity is therefore extremely small, and may, 
for the purposes of calculation from the data of the next experiment, be neglected. 
Experiment B 
Sciatic Nerve of cat immediately removed from the animal after death. 
Measurements taken before and after immersion in a 1^49 grammes per cent, solution of potassium 
chloride (i normal solution), for five minutes, at i8°C. 
Before 
After 
Weight 
•2035 grammes 
Weight 
1 99 5 grammes 
Length 
5 centimetres 
Length 
5 centimetres 
Resistance 
22,276 ohms 
Resistance ... 20 
,500 ohms 
Specific resistance 
181 ohms 
Specific resistance 
1 64 ohms 
Specific conductivi 
mercury at 
ty j2"7 in terms of 
i8°C x 10- 8 
Specific conductivity 
mercury at 1 8° C 
58*1 in terms of 
X IO — 5 
In this experiment there is a considerable alteration in the ' specific conductivity.' 
This increase is also not to be explained by the addition of a new cylindrical covering 
of solution in excess of its pre-exisistent one, since the weight has diminished by 
4 milligrammes, most probably by the abstraction of water from the internal solution.* 
* Preliminary Communication, Proceedings Royal Society; 67, 317. 
R 
