In 1882 Charcot and Magnan published in the _Archives de Neurologie_ the first important study which appeared in France concerning sexual inversion and allied sexual perversions.

They regarded sexual inversion as an episode (_syndrome_) in a more fundamental process of hereditary degeneration, and compared it with such morbid obsessions as dipsomania and kleptomania.

From a somewhat more medico-legal standpoint, the study of sexual inversion in France was furthered by Brouardel, and still more by Lacassagne, whose stimulating influence at Lyons has produced fruitful results in the work of many pupils.[120] Of much more importance in the history of the theory of sexual inversion was the work of Richard von Krafft-Ebing (born at Mannheim in 1840 and died at Graz in 1902), for many years professor of psychiatry at Vienna University and one of the most distinguished alienists of his time.

While active in all departments of psychiatry and author of a famous textbook, from 1877 onward he took special interest in the pathology of the sexual impulse.

His _Psychopathia Sexualis_ contained over two hundred histories, not only of sexual inversion but of all other forms of sexual perversion.
For many years it was the only book on the subject and it long remained the chief storehouse of facts.