CHAPTER X 
RESPONSE IN METALS 
Is response found in inorganic substances ?—Experiment on tin, block 
method—Anomalies of existing terminology—Response by method of 
depression—Response by method of exaltation. 
We have now seen that the electrical sign of life is not 
confined to animals, but is also found in plants. And 
we have seen how electrical response serves as an index 
to the vital activity of the plant, how with the arrest of 
this vital activity electrical response is also arrested 
temporarily, as in the case amongst others of anes- 
thetic action, and permanently, for instance under the 
action of poisons. Thus living tissues—both animal 
and vegetable—may pass from a responsive to an irre- 
sponsive condition, from which latter there may or may 
not be subsequent revival. 
Hitherto, as already said, electrical response in 
animals has been regarded as a purely physiological 
phenomenon. We have proved by various tests that 
response in plants is of the same character. And we 
have seen that by physiological phenomena are gene- 
rally understood those of which no physical explana- 
tion can be offered, they being supposed to be due to 
the play of some unknown vital force existing in living 
substances and giving rise to electric response to stimu- 
lation as one of its manifestations. 
