INORGANIC RESPONSE 147 
to students of physiological response but also known in 
medical practice, namely that of the opposite effects pro- 
duced by the same reagent when given in large or in 
small doses. Here, too, we have the same phenomena 
reproduced in an extraordinary manner in inorganic 
response. The same reagent which becomes a ‘ poison’ 
in large quantities may act as a stimulant when applied in 
small doses. This is seen in record fig. 94, m which 
(a) gives the normal responses in water ; KHO solution 
was now added so as to make the streneth three parts in 
1,000, and (6) shows the consequent enhancement of 
response. A further quantity of KHO was added so 
as to increase the strength to three parts in 100. This 
caused a complete abolition (c) of response. 
It will thus be seen that as in the case of animal 
tissues and of plants, so also in metals, the electrical 
responses are exalted by the action of stimulants, 
lowered by depressants, and completely abolished by 
certain other reagents. The parallelism will thus be 
found complete in every detail between the phenomena 
of response in the organic and the inorganic. 
