the eighth or tenth part of a second." [Force and Matter, New York, 1891, p. 241.]
Heat and light, being modes of motion, 'phosphorescence' and 'incandescence' are phenomena to which consciousness has been likened by the production-theory: "As one sees a metallic rod, placed in a glowing furnace, gradually heat itself, and—as the undulations of the caloric grow more and more frequent—pass successively from the shades of bright red to dark red (sic), to white, and develope, as its temperature rises, heat and light,—so the living sensitive cells, in presence of the incitations that solicit them, exalt themselves progressively as to their most interior sensibility, enter into a phase of erethism, and at a certain number of vibrations, set free (dégagent) pain as a physiological expression of this same sensibility superheated to a red-white." [J. Luys: le Cerveau, p. 91.]
In a similar vein Mr. Percival Lowell writes: "When we have, as we say, an idea, what happens inside of us is probably something like this: the neural current of molecular change passes up the nerves, and through the ganglia reaches at last the cortical cells. . . . When it reaches the cortical cells, it finds a set of molecules which are not so accustomed to this special change. The current encounters resistance, and in overcoming this