ELECTRIC RESPONSE 13 
advantage of being applicable in cases where the latter 
cannot be used. 
Electrical response: A measure of physiological 
activity.—These electrical changes are regarded as 
physiological, or characteristic of living tissue, for any 
conditions which enhance physiological activity also, 
pari passu, increase their intensity. Again, when the 
tissue is killed by poison, electrical response disappears, 
the tissue passing into an irre- 
sponsive condition. Anesthetics, M 
like chloroform, gradually di- 
minish, and finally altogether 
abolish, electrical response. 
From these observed facts— 
that living tissue gives response 
while a tissue that has been 
killed does not—it is concluded 
that the phenomenon of re- 
sponse is peculiar to living OY Fyre. 5.—Stwvnranzous Recorp 
= 1 - ‘ e oF THE MecuHanicat (M) anp 
ganisms.’ The response pheno (By EdGtart in Theor eat Ge 
mena thatwe have beenstudying "#8 ee or Frog. (Wat- 
7 LER. 
are therefore considered as due 
to some unknown, super-physical ‘ vital’ force and are 
thus relegated toa region beyond physical inquiry. 
1 «The Electrical Sign of Life. . . An isolated muscle gives sign of life 
by contracting when stimulated. . . . An ordinary nerve, normally con- 
nected with its terminal organs, gives sign of life by means of muscle, 
which by direct or reflex path is set in motion when the nerve trunk is 
stimulated. But such nerve separated from its natural termini, isolated 
from the rest of the organism, gives no sign of life when excited, either in 
the shape of chemical or of thermic changes, and it is only by means of an 
electrical change that we can ascertain whether or no it is alive . . . The 
most general and most delicate sign of life isthen the electrical response.’— 
Waller, in Brain, pp. 5 and 4, Spring 1900. 
