THE INJURY CURRENT OF NERVE 261 
The conductivity of nerve is now expressed in a form in which it can con- 
veniently be compared to that of solutions of electrolytes. Thus, taking solutions 
of NaCl as our standards of comparison, we have the following determined specific 
conductivity of such solutions. 1 
Specific Conductivity of Solutions of NaCl 
Concentration of Solution 
Specific Conductivity 
Gram molecules 
per litre 
Grammes per 
cent. 
in terms of 
Mercury 
TOO 
5-620 
695-0 x 
10— 8 
0 - 50 
2-865 
378-5 x 
io~ 8 
cr 1 0 
0-583 
86-5 x 
IO — 8 
0*05 
0-292 
44-8 x 
IO -8 
The specific conductivity of nerve is, therefore, approximately the same as that 
of a solution of sodium chloride of "35 grammes per cent, concentration. In other 
words, the conductivity of the nerve would, so far as we are at present considering it, be 
adequately imitated by that of a saline solution occupying the same space, which was only 
half the strength of the ordinary ' normal saline^ solution. 
It is of interest to compare the value so obtained with that of previous investi- 
gators. The data given by I. Tereg 1 are presented in a form most suitable for 
comparison. This author, in a general examination of the conductivity of the 
tissues and the modifications produced by changes of temperature, obtained a value 
for the resistance of nerves as follows : — The nerves were laid side by side in an 
accurately calibred hard glass tube (diameter 1 2 mm.) The length of the tube used 
was 34' 5 mm. The nerves were presumably packed closely in this tube and accurately 
cut to the required length. Amalgamated zinc electrodes were brought to each end 
of the tube and the resistance of the enclosed nerves determined. 
The following values are given for this resistance : — 
At 21° C. ... ... ... 700 ohms. 
25° C. ... ... ... 670 „ 
32 0 C. ... ... ... 600 „ 
35 0 C. ... ... ... 570 „ 
39° C. ... ... ... 530 „ 
45 0 C. ... ... ... 460 „ 
G 
1. Kohlrausch, IViedeman s Annul, XXVI., p. io,<;. 
I. Archiv. fur Anat. : unit Physiologic, 1899, p. 
