Charles Edward Brown-Séquard (1817-1894), British physiologist and neurologist, was born at Port Louis, Mauritius, on the 8th of April 1817. His father was an American and his mother a Frenchwoman, but he himself always desired to be looked upon as a British subject, though in the restlessness of his life and the enthusiasm of his disposition, characteristics of his mother's nation were plainly visible. After graduating in medicine at Paris in 1846 he returned to Mauritius with the intention of practising there, but in 1852 he went to America. Subsequently he returned to Paris, and in 1859 he migrated to London, becoming physician to the national hospital for the paralysed and epileptic. There he stayed for about five years, expounding his views on the pathology of the nervous system in numerous lectures which attracted considerable attention. In 1864 he again crossed the Atlantic, and was appointed professor of physiology and neuro-pathology at Harvard. This position he relinquished in 1867, and in 1869 became professor at the école de Médecine in Paris, but in 1873 he again returned to America and began to practise in New York. Finally, he went back to Paris to succeed Claude Bernard in 1878 as professor of experimental medicine in the Collège de France, and he remained there till his death, which occurred on the 2nd of April 1894 at Sceaux. Brown-Séquard was a keen observer and experimentalist.

He contributed largely to our knowledge of the blood and animal heat, as well as many facts of the highest importance on the nervous system. He was the first scientist to work out the physiology of the spinal cord, demonstrating that the decussation of the sensory fibres is in the cord itself. He also did valuable work on the internal secretion of organs, the results of which have been applied with the most satisfactory results in the treatment of myxoedema. Unfortunately in his extreme old age, he advocated the hypodermic injection of a fluid prepared from the testicles of sheep, as a means of prolonging human life. It was known, among scientists, derisively, as the Brown-Séquard Elixir. His researches, published in about 500 essays and papers, especially in the Archives de Physiologie, which he helped to found in 1868, cover a very wide range of physiological and pathological subjects.