ELECTRIC RESPONSE 



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. Anaesthetics, 

 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 or- Fm< 5 .__ SlMULTANEODS EECORD 

 ganisms. 1 The response pheno- 

 mena that we have been study ing 

 are therefore considered as due 

 to some unknown, -super-physical ' vital ' force and are 

 thus relegated to a 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 is then the electrical response.' 

 Waller, in Brain, pp. 3 and 4, Spring 1900. 



OF THE MECHANICAL (M) AND 

 (E) ELECTRICAL EESPONSES OF 

 THE MUSCLE OF FROG. (WAL- 

 LER.) 



