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1. Molecular disturbance produced by mechanical stimulation gives rise to an electromotive response. In the majority of cases, under normal conditions, the responsive electrical current in a wire is from the less to the more stimulated.

2. Response may be obtained by (1) method of block, (2) by methods of negative or positive variation.

3. The electromotive response disappears on the cessation of stimulus.

4. The intensity of the electrical response is modified by the molecular condition of the wire. Annealing, or previous stimulation enhances the electric response.

5. Abnormal response due to molecular modification is transformed into normal by previous stimulation.

6. The intensity of electric response is increased with increasing intensity of stimulation.

7. In a curve showing the relation between intensity of stimulus and resulting response, the first part is slightly convex to the abscissa, the second is approximately straight, and the third concave. The response tends to reach a limit.

8. Minimally effective stimulus becomes effective by summation of stimuli. A maximum effect is produced, determined by the intensity of individual stimulation.

9. Hysteresis is exhibited in cyclic curves. The forward and return curves tend to coincide after several cycles. Previous annealing reduces hysteresis, and after one or two cycles the wire assumes a constant sensitivity.

10. Chemical reagents may profoundly modify the electric excitability. Some of them increase the excitability, while others depress or abolish it.