260 
THOMPSON YATES LABORATORIES REPORT 
gravity the error is left uncorrected ; since it appears only once in the value of the 
specific conductivity, and is, therefore, not increased by multiplication to a higher 
power. 
The ' specific ' resistance of the nerve is taken as that of a closely packed pile of 
similar nerves, one centimetre in length, and offering a united cross section of one 
square centimetre. 
In any single case such a { specific ' value may be found by dividing the value of 
the resistance by the length and multiplying by the ascertained value of the cross 
section. 
Specific resistance 
volume 
length length 
I weight 
or approximately ... = r x 
length length 
Thus taking the figures obtained as the average of the data of the eleven 
experiments — 
•221 
The specific resistance of the sciatic nerve of the cat = 19,500 x — ; 
4*8 x 4 ' 
= 180 ohms (approx). 
Similar values given from the eleven separate experiments are — 
ohms. 
I 
II 
III 
IV 
V 
VI 
195 ohms 
146 „ 
165 „ 
195 » 
176 „ 
160 „ 
VII .. 
VIII .. 
IX .. 
X .. 
XI .. 
183 ohms 
163 „ 
I9 1 » 
205 „ 
165 „ 
Taking the average value of 1 80 ohms, it is of interest for purposes of comparison to 
compare it with the specific resistance of mercury at 1 8° C, with which value the re- 
sistance of solutions of electrolytes is commonly compared. 
The specific resistance of mercury at 0° C. 
The temperature co-efficient 
.•. The specific resistance of mercury at 18* C. 
The specific resistance of nerve 
94-07 x io - 6 ohms 
•00077 
95-4 x 10- 6 „ 
180 
95-4 X 10 
-6 
The specific resistance of mercury 
= 1-885 x 106 .» 
Taking the ' specific conductivity ' of nerve to be the reciprocal of its ' specific 
resistance,' as defined above, it is equal to — 
1 
; 5 
X IO 
—6 
= 53 x io -8 in terms of mercury at 18° C. 
