Mr Pussin, the governor… In his Treatise on Insanity of 1801 and repeatedly thereafter Pinel acknowledged his indebtedness to Jean-Baptiste Pussin and to Madame Pussin. They are often referred to as the governor and governess in Pinel's case reports. Jean-Baptiste Pussin was born in 1745, only five months after Pinel. He worked as a tanner before he was admitted to the Bicêtre in 1771 for scrofula, which was "cured." As often happened with former patients, he found employment at the hospital, first on the boy's ward and then, in 1784, as superintendent of the ward for incurable mental patients. In 1786 he married Marguerite Jubline, who was nine years younger than him. They worked together caring for patients at Bicêtre. Pinel met Pussin there in 1793, at the height of the reign of terror. Pinel gave a candid account of his relationship with Pussin in the years 1793-95:
The dogmatic tone of the doctor was abandoned from that point on [ie., from the moment that Pinel realized that Pussin had a great deal to teach him]. Frequent visits, sometimes during several hours of the day, helped me to familiarize myself with the deviations, vociferations and extavances of the most violent maniacs. From that point on, I had repeated conversations with the man best acquainted with their anterior condition and delirious ideas: utmost attention to humor all the pretensions of his amour-propre, questions that were varied and went back over the same material when the answers were obscure, no objections on my part when what he advanced was doubtful or improbable, but a tacit return to further examination inorder to illuminate or rectify it.
Pinel  appreciated Pussin's contribution so greatly that in 1802 he arranged to have a position created for Pussin at the Salpêtrière, where Pinel was then working, at a salary ordinarily reserved for doctors.
 

See: Dora B. Weiner, "The Apprenticeship of Philippe Pinel: A New Document, 'Observations of Citizen Pussin on the Insane," American Journal of Psychiatry ,136 [1979] 1128-1134.
See: Jan Goldstein, Console and Classify:The French Psychiatric Profession in the Nineteenth Century, [Cambridge UP, 1987] 72-80
See: Weiner, 1999, 135-8.