Jagadish Chandra Bose

“ According to my theory, upon which the invention is based, the changes produced on or in the sensitive substance of a coherer or detector by electrical disturbances, Hertzian waves, light-waves, and other radiations are due to molecular distortion. In order to obtain the best results with a detector or coherer, it is necessary that this distortion shall be removed before the detector or coherer receives fresh radiations—as, for example, the signals in wireless or other telegraphy. ”

“ Of the substances which give a characteristic curve, such as just described, some have the property of presenting a decreasing resistance to the passage of the electric current with an increasing impressed electromotive force, while others have the opposite property—namely, that of presenting an increased resistance as the impressed force increases. ”

“ In order, however, that the apparatus to which this invention relates shall work to the best advantage, it is desirable that the distortion, whether positive or negative, produced by the light-wave or other radiation shall not only be readily detected and indicated, but also that the substance shall return to its normal state upon the cessation of the impressed radiation. For this reason it is desirable to use substances having a characteristic curve of the kind above referred to or to provide means whereby said substances shall be caused to give such characteristic curve. ”