At one stage of his long career, Sir Jagadis Chunder Bose undertook an examination of inorganic matter in the same way as a biologist examines a muscle or a nerve. He subjected metals to various kinds of stimulus—mechanical, thermal, chemical, and electrical. He found that all sorts of stimulus produce an excitatory change in them. This excitation sometimes expresses itself in a visible change of form, and sometimes not; but the disturbance produced by the stimulus always exhibits itself as an electric [more...]