Response in the Living and Non-Living

by Jagadis Chandra Bose

Fig. 53.—Method of Exaltation

The contact B is made more excitable by chemical stimulant (Na₂CO₃). The current of response is towards the more excitable B.

Method of exaltation.—A still more striking corroboration of these results may, however, be obtained by the converse process of relative exaltation of the responsiveness of one contact. This may be accomplished by touching one contact, say B, with a reagent which like Na₂CO₃ exalts the electric excitability. On stimulation of the wire, the current of response is towards the more excitable B ([fig. 53]).

I give four records ([fig. 54]) which will clearly exhibit the responses as obtained by the methods of relative depression or exaltation. In (a) B is touched with the excitant Na₂CO₃, a permanent current flows from A to B, response to stimulus is in the same direction as the permanent current (positive variation). In (b) B is touched with a trace of the depressant oxalic acid, the permanent current is in the same direction as before, but the current of response is in the opposite direction (negative variation). In (c) B is touched with dilute KHO, the response is exhibited by a positive variation. In (d) B is touched with strong KHO, the response is now exhibited by a negative variation. The last two results, apparently anomalous, are due to the fact, which will be demonstrated later, that KHO in minute quantities is an excitant, while in large quantities it is a depressant.

Fig. 54

Permanent Current Current of Response B treated with sodium carbonate. → → B treated with oxalic acid → ← B treated with very dilute potash → → B treated with strong potash → ← Current of response is always towards the more excitable point.

(a) Response when B is treated with sodium carbonate.—An apparentpositive variation. (b) Response when B is treated with oxalic acid.—An apparent negativevariation. (c) Response when B is treated with very dilute potash.—Positivevariation. (d) Response when B is treated with strong potash.—Negativevariation. The response is up when B is more excitable, and down when A is moreexcitable. Lines thus ------ indicate deflection due to permanent current.

• (a) Response when B is treated with sodium carbonate.—An apparent positive variation.
• (b) Response when B is treated with oxalic acid.—An apparent negative variation.
• (c) Response when B is treated with very dilute potash.—Positive variation.
• (d) Response when B is treated with strong potash.—Negative variation.

We have thus seen that we may obtain response (1) by block method, (2) by the method of injury, or relative depression of responsiveness of one contact, and (3) by the method of relative exaltation of responsiveness of one contact. In all these cases alike we obtain a consistent action current, which in tin is normally positive, or towards the relatively more excited.