82 RESPONSE IN THE LIVING AND NON-LIVING 
Is response found in inorganic substances ? '—It is 
now for us, however, to examine into the alleged super- 
physical character of these phenomena by stimulating 
inorganic substances and discovering whether they do 
or do not give rise to the same electrical mode of re- 
sponse which was supposed to be the special character- 
istic of living substances. We shall use the same apparatus 
and the same mode of stimulation as those employed in 
obtaining plant response, merely substituting, for the stalk 
of a plant, a metallic wire, say ‘ tin’ (fig. 50). Any other 
metal could be used instead of tin. 
Experiment on tin, block method.—Let us then take 
a piece of tin wire’ from which all strains have been 
previously removed by annealing, and hold it clamped 
in the middle at c. If the strains have been success- 
fully removed A and B will be found iso-electric, 
and no current will pass through the galvanometer. 
If A and B are not exactly similar, there will be a 
slight current. But this will not materially affect the 
results to be described presently, the slight existing 
current merely adding itself algebraically to the current 
of response. 
If we now stimulate the end A by taps, or better 
1 Following another line of inquiry I obtained response to electric 
stimulus in inorganic substances using the method of conductivity 
variation (see ‘De la Généralité des Phénoménes Moléculaires Produits 
par l’Electricité sur la Matiére Inorganique et sur la Matiére Vivante,’ 
Travaux du Congres International de Physique, Paris, 1900; and also ‘On 
Similarities of Effect of Electric Stimulus on Inorganic and Living 
Substances, British Association 1900. See Electrician). To bring out 
the parallelism in all details between the inorganic and living response, 1 
have in the following chapters used the method of electro-motive variation 
employed by physiologists. 
2 By ‘tin’ is meant an alloy of tin and lead used as electric fuse. 
