Response in the Living and Non-Living

by Jagadis Chandra Bose

I found that traces of after-effect due to the application of Na₂CO₃ remain for a time. If the reagent is previously applied to an area and the traces of the carbonate then washed off, the increased sensitiveness conferred disappears gradually. Again, if we apply Na₂CO₃ solution to a fresh point, the sensitiveness gradually increases. There is another further interesting point to be noticed: the beginning of response is earlier when the application of Na₂CO₃ is fresh.

Fig. 68.—Continuous Transformation from Negative To Positive through Intermediate Diphasic Response

Thick dots represent the times of application of successive stimuli.

We have thus a wire held at one end, and successive uniform vibrations at intervals of one minute imparted to the wire as a whole, by means of a vibration head on the other end.

Owing to the after-effect of previous application of Na₂CO₃ the sensitiveness of B is at the beginning great, hence the three resultant responses at the beginning are negative or downward.

Dilute solution of Na₂CO₃ is next applied to A. The response of A (up) begins earlier and continues to grow stronger and stronger. Hence, after this application, the response shows a preliminary positive twitch of A followed by negative deflection of B. The positive grows continuously. At the fifth response the two phases, positive and negative, become equal, after that the positive becomes very prominent, the negative being reduced as a feeble after-vibration.

It need only be added here that the diphasic variations as exhibited by metals are in every way counterparts of similar phenomena observed in animal tissues.

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