636 



Professor Jcujadis Chunder Bose 



[May 10, 



could offer no parallel. For they involve possibilities which we have 

 regarded as exclusively physiological. Accustomed in animal 

 bodies to see the responsive pass into the irresponsive state at the 

 moment of death, we look on this sequence as peculiar to the world 

 of the living. And on this fact is based the supreme test by which 

 physical and physiological phenomena are differentiated. That only 

 can be called living which is capable of dying, we say, and death can 

 be accelerated by the administration of poison. The sign of life as 

 given by the electric pulses then wanes, till it ceases altogether. 

 Molecular immobility — the rigor of death — supervenes, and that 

 which was living is no longer alive. 



Is it credible that we might, in like manner, kill inorganic re- 

 sponse by the administration of poison? Could we by this means 

 induce a condition of immobility in metals, so that, under its influ- 

 ence, their electric pulsations should wane and die out altogether ? 



Before we attempt the action of poisons let us study the exciting 

 effect of stimulants. You observe in the galvanometer scale the 



normal extent of response under 

 successive uniform stimuli applied 

 to one wire of the cell. I now add 

 a few drops of sodium carbonate 

 to the water in the cell and you 

 observe the growing exaltation of 

 the response. There are other 

 stimulants besides this which would 

 induce a still higher increase of 

 sensibility, even to an astonishing 

 degree* (Fig. 16). 



I now pass on to the effect of 

 poisons. Any of the substances 

 already enumerated may be used 

 as the toxic agent. I take a fresh cell, and first demonstrate before 

 you its normal electrical pulsation. By means of a pipette I now 

 inject into the cell the toxic dose. Its effect is at once evident to 

 you. After a few preliminary flutterings the electric pulses cease 

 to beat, and all our efforts, by intense stimulation to reawaken them, 

 fail (Fig. 17). 



But we may, sometimes at least, by the timely application of a 

 suitable antidote, revive the dying response, as I do now, by an 

 appropriate injection. See how the lethargy of immobility passes 

 away ; the pulse-throb grows stronger and stronger, and the response 

 in our piece of metal becomes normal once more (Fig. 10). 



There remains the very curious phenomenon, known not only to 



Fig. 16. — Curves showing stimu- 

 lating action of Na 2 C0 3 . The three 

 curves to the left show normal re- 

 sponse; the four to the right increased 

 response after addition of Na 2 C0 3 . 



* The external resistance, as has been said previously, is kept very large, 

 and the slight variation of the internal resistance of the cell has no effect on the 

 deflection. The increased response can also be shown by capillary electrometer. 

 Note also the disappearance of response by the influence of large dose. 



