When did we come to think of memory, language, and emotion as "hard-wired" functions of the brain? We will explore the origins of this enduring metaphor by revisiting the explosion of brain research during the 19th century. Developments in pathological research shined a light on the brain's physiology, but psychologists, philosophers, and neurologists looked outside the laboratory to uncover the nature of cerebral matter. Their conversations converged around advances in communications technologies - from the telegraph, to the telegram and telephone - which furnished a new language for the "circuitry" of the space between our ears. Yet that language, far from having resolved the problem of the mind's relation to the body, instead supported the arguments of materialists and idealists alike. The brain's history, as we will see, was not limited to scientific discoveries, but unfolded at the intersections of machinery, selfhood, and society.