too RESPONSE IN THE LIVING AND NON-LIVING 
CHAPTER Xai 
INORGANIC RESPONSE—METHODS OF ENSURING CONSISTENT 
RESULTS 
Preparation of wire—Effect of single stimulus. 
I SHALL now proceed to describe in detail the response- 
curves obtained with metals. The E.M. variations 
resulting from ‘stimulus range, as has been said, from 
‘4 volt to ‘01 of that value, according to the metal 
employed. And as these are molecular phenomena, the 
effect will also depend on the molecular condition of 
the wire. 
Preparation of wire.—In order to have our results 
thoroughly consistent, it 1s necessary to bring the wire 
itself into a normal condition for experiment. The 
very fact of mounting it in the cell strains it, and 
the after-effect of this strain may cause irregularities in 
‘the response. 
For the purpose of bringing the, wire to this normal 
state, one or all of the following devices may be used 
with advantage. (1) The wires obtained are usually 
wound on spools. It is, therefore, advisable to straighten 
any given length, before mounting, by holding it 
stretched, and rubbing it up and down with a piece of 
cloth. On washing with water, they are now ready for 
mounting in the cell. 
