Charcot (1825-1893) brought new vigor to the clinicopathologic tradition of the Paris school by adding to macroscopic anatomy the new dimension of histology--still marginal in France when, in 1862, he came to the Salpêtrière and undertook the exploration of its enormous resources in pathology. Vulpian was the initiator. Cornil, Charcot's intern in 1863, taught him the techniques which he had acquired from Virchow's laboratory. Within a decade, Charcot established the bases for a neurological classification which have endured. He described multiple sclerosis. He attributed progressive and acute muscular atrophy to lesions of anterior horns of the spinal cord; locomotor ataxia to the posterior horn and spinal root. He gathered together the data leading to the description of amyotrophic lateral sclerosis. In 1872 (in fact 1873) he replaced Vulpian in the chair of pathological anatomy which he held for ten years. His lessons in pathology of the viscera; kidney, liver, and bile ducts, lung, make up several volumes of his Completes Works. In the study of Localizations of diseases of the spinal cord (1873-74), he specified the anatomy and physiology of the cord. In 1875, and then in 1880, the Cerebral localizations of motor activities marked a decisive step. By 1882, when the clinical chair for the diseases of the nervous system was inaugurated, Charcot was already substantially involved in the study of hysteria. He approached that subject from a perspective that remained loyal to pathology setting up by analogy an ongoing correspondence in terms of anatomical sites, between the "dynamic lesion" assumed to be responsible for manifestations of the neurosis, and organic lesions which produced the same symptoms.