1901.] on the Response of Inorganic Matter to Stimulus. 625 



organic living and the inorganic or non-living. The phenomena of 

 the inorganic are dominated merely by physical forces, while on tho 

 other side of the chasm, in the domain of the living, inscrutable vital 

 phenomena, of which electric response is the sign-manual, suddenly 

 come into action. 



But is it true that the inorganic are irresponsive ? That forces 

 evoke in them no answering thrill? Are their particles for ever 

 locked in the rigid grasp of immobility? As regards response, is 

 the chasm between the living and inorganic really impassable ? 



Thanks to the courtesy of the authorities of the Davy-Faraday 

 Laboratory, I have been enabled to complete the investigations on 

 this subject, commenced in India, under this very roof. I shall now 

 proceed to submit the question before you to an experimental test. 



Inorganic 

 Response. 



Taking a piece of tin wire, I arrange it in exactly 

 the same way as the stalk of the horse-chestuut 

 (see Figs. 6 and 8). That is to say, it is clamped 

 in the middle, and secure electrolytic contacts are 

 made, through non-polarisable electrodes, which lead to a galvano- 

 meter. If all strains have been completely removed, the two points, 

 A and B, will be found iso-electric. 

 If now I take the end A and strike 

 it, or subject it to torsional vibration, 

 you will observe that the galvano- 

 meter spot on the screen, hitherto 

 quiescent, moves in one direction, 

 showing the existence of the " current 

 of action." I stop the disturbance, 

 and you watch it creeping back to its 

 original position, exhibiting a com- 

 plete recovery. As long as the wire 

 is excited, so long will the electric 

 variation persist. Greater intensity 

 of vibration will produce greater 

 electric variation. Stimulation of the 

 B end will produce a deflection in 

 the opposite direction. 



Or, following experiment 3, we may demonstrate the fact of 

 electric resjionse by the method of injury. One end of the wire is 

 touched with KHO, and the usual current of injury is observed. On 

 now stimulating the wire, a diminution of this current of injury, or 

 negative variation, will be produced. 



Fig. 8. — Experimental arrange- 

 ment to show electric response in 

 metallic wires. C, clamp. 



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. 

 Vol. XVI. (No. 95.) 2 t 



