The motor mechanism of plants / by Sir Jagadis Chunder Bose.

  • Jagadish Chandra Bose
Date:
1928
Catalogue details

Licence: In copyright

Credit: The motor mechanism of plants / by Sir Jagadis Chunder Bose. Source: Wellcome Collection.

    45/469 (page 12)
    high. I discovered afterwards that Mimosa,, in an optimum condition, was ten times more sensitive to an electric shock than a human being. It will further be shown that a shock individually ineffective becomes effective on repetition, the plant may thus be stimulated by subjecting it to a number of feeble shocks, which cause no injury to the tissue. Ihe intensity of the shock can be gradually increased by bringing the primary coil nearer the secondary (fig. 3). Instead of a single make-or-break shock, alternating Fig. 3. Arrangement for applying induction-shock. k, key in the primary circuit. The secondary circuit may be short-circuited by the second key. induction-shocks can be produced by an automatic spring- interrupter, included in the primary circuit. The duration of stimulation is adjusted by a metronome which completes the primary circuit for a definite length of time. The intensity of the exciting shock which I have adopted as the unit, is one which barely induces a perceptible sen- sation in man. The observer dips two fingers, one of each hand, into two troughs of saline solution, which are in series with the experimental Mimosa and the secondary coil. This coil, at first placed at a great distance, is gradually brought nearer the primary till, at a certain scale-reading, the observer just begins to perceive the shock. This scale division is marked as 1. The other positions of the scale are marked in terms of this unit. The calibration is