This inquiry which Dr. J. C. Bose started for the purpose of ascertaining 'coherer action'--why the "receiver" had to be tapped in order to respond again to electric waves--took him unconsciously to the border region of physics and physiology and gave an altogether new turn to his researches. "He found that the uncertainty of the early type of his receiver was brought on by 'fatigue' and that the curve of fatigue of his instrument closely resembled the fatigue curve of animal muscle."[13] He did not stop there but pushed on his investigations and found "that the 'tiredness' of his instrument was removed by suitable stimulants and that application of certain poisons, on the other hand, permanently abolished its sensitiveness." He was amazed at this discovery--this parallelism in the behaviour of the 'receiver' to the living muscle. This led him to a systematic study of all matter, Organic and Inorganic, Living and Non-Living. RESPONSE IN LIVING AND NON-LIVING He began 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. And this excitation sometimes expresses itself in a visible change of form and sometimes not; but the disturbance produced by the stimulus always exhibits itself in an _electric response_. He next subjected plants and animal tissues to various kinds of stimulus and also found that they also give an _electric response_. Finding that a universal reaction brought together metals, plants and animals under a common law, he next proceeded to a study of _modifications in response_, which occur under various conditions. He found that they are all benumbed by cold, intoxicated by alcohol, wearied by excessive work, stupified by anaesthetics, excited by electric currents, stung by physical blows and killed by poison--they all exhibit essentially the same phenomena of fatigue and depression, together with possibilities of recovery and of exaltation, yet also that of permanent irresponsiveness which is associated with death--they all are responsive or irresponsive under the same conditions and in the same manner. The investigations showed that, in the entire range of response phenomena (inclusive as that is of metals, plants and animals) 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."[14] SECOND SCIENTIFIC DEPUTATION, 1900-01