Click portrait to view at full size.

Bell has been called the father of physiological psychology. In his privately published Idea of a New Anatomy of the Brain (1811) Bell described his experiments thus: “On laying bare the roots of the spinal nerves, I found that I could cut across the posterior fasciculus of nerves, which took its origin from the posterior portion of the spinal marrow without convulsing the muscles of the back; but that on touching the anterior fasciculus with the point of the knife, the muscles of the back were immediately convulsed. Such were my reasons for concluding that the cerebrum and the cerebellum were parts distinct in function. François Magendie established that the posterior roots are sensory and the anterior roots motor in 1822. This clear evidence for a functional division in the central nervous system was of tremendous import, as much of the subsequent research involved pursuing this division to ever higher centres. It also provided a physiological basis for localization of function, in accord with Gall’s psychological speculations. Bell traced the course of the nerves from the senses to specific areas of the brain, thereby suggesting a principle of specific nerve energies: “It is provided, that the extremities of the nerves of the senses shall be susceptible each of certain qualities in matter; and betwixt the impression of the outward sense, as it may be called, and the exercise of the internal organ, there is established a connection by which the ideas excited have a permanent correspondence with the qualities of bodies which surround us”. In a later paper to the Royal Society he described the muscle or proprioceptive sense and distinguished by experiment the consequences of active and passive eye movements on visual direction. Bell was born and died in Edinburgh, although he made his mark in London. The portrait shows Bell, aged thirty, shortly after he had moved to London to practice surgery and eventually to establish a medical school. The previous year he had written the third volume of the Anatomy of the Human Body (1803), with his oldest brother, John, who was a noted Edinburgh surgeon. The title page of the volume is also shown. His arrival in London was inauspicious, as few knew of his work, but with the publication of his Essays on the Anatomy of Expression in Painting (1806), combining his artistic talents and anatomical knowledge, he became widely recognized. The nerves of the head, in which Bell’s portrait is shown, was originally drawn by him, and it appeared in the third edition of the book. He demonstrated that the muscles of expression are controlled by the seventh cranial nerve, damage to which can result in Bell’s palsy.