Before 1870, the doctrine that the cerebral cortex was inexcitable to artificial stimulation was generally held by investigators. As early as 1756, Haller1reported a series of experiments performed six years before on dogs, cats and goats by his pupil Zinn, in which he was unable to produce muscular movements by mechanical or chemical irritation applied to the cerebral cortex. Later investigators, including Magendie,2Longet,3Budge4and Matteucci,5were also unable to produce movements by various methods of artificial stimulation, including the use of the galvanic current. On the basis of such results reported by the leading experimentalists of their time, it is not surprising to find that investigators generally agreed that muscular movements could not be obtained on irritation of the cerebral cortex. In addition to denying the possibility of artificial excitation of this part of the central nervous system, it was almost universally