250 
THOMPSON YATES LABORATORIES REPORT 
TABLE OF PRELIMINARY EXPERIMENTS 
Resistance of the Vagus Nerve of the Dog from Seven Separate 
Experiments 
Number 
of 
Experiment 
Length of 
Nerve 
in 
Centimetres 
Number 
01 
Sections 
Resistance in Ohms 
Excess 
Direct 
Measurement 
Su mmation 
of Resistance 
of Parts 
In Ohms 
Per Cent. 
I 
8 
5 
100,952 
I 28,720 
27,768 
27-5 
II 
8-3 
5 
121,5 OO 
149,500 
28,000 
29-1 
III 
7-8 
+ 
88,500 
105,950 
i7>45° 
197 
IV 
7 - 3 
.4 
9 1,000 
I I 1 ,000 
20,000 
22 - 0 
V 
6-2 
4 
70,900 
94,780 
23,880 
3 3'6 
VI 
5"3 
3 
65,200 
82,400 
T 7,200 
2 6'3 
VII 
oo 
3 
50,200 
79,200 
29,200 
36.6 
A consideration of such evidence and of the probabilities of the case examined 
by themselves make the avoidance of values obtained by direct measurement for the 
resistance ot short stretches of nerve a matter of necessity. It seems clear 
that the resistance per centimetre obtained from the measurement of the longest 
stretch of nerve available, provided, if possible, with two cross sections, is a 
measurement as free as possible from errors due to transverse resistance and polariza- 
tion phenomena, and gives the best determination of the gross longitudinal resistance 
of the nerve. 
In the following experiments, therefore, all resistances have been directly 
determined, but the directly determined resistances of the shorter stretches of nerve 
are not used for purposes of calculation. The nerves were laid upon an ebonite ruled 
scale during the measurement of resistances and the distances of the electrodes from 
one another were read upon the scale and noted, from these lengths the resistances 
of the shorter stretches of nerve have been calculated by use of the standard resistance 
per centimetre obtained from the whole length of nerve. Both values are, however, 
given to show the magnitude of the error thus avoided, and also to serve as material 
for the purposes of any criticism directed against this method of procedure s 
