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 response. His investigations showed that, in the entire range of response phenomena (regardless of whether the subject is metallic, plant or animal in origin) there is no breach of continuity; that "the living response in all its diverse modifications is only a repetition of responses seen in the inorganic" and that the phenomena of response "are determined, not by the play of an unknowable and arbitrary vital force, but by the working of laws that know no change, acting equally and uniformly throughout the organic and inorganic matter."