[The work of R.T.H. Laennec at the Necker Hospital, then Charity Hospital from 1821 to 1826].

His bad health obliged RTH Laennec to interrupt his hospital activities from 1819 to 1821. He goes back to his head functions in Necker's then Charity's Hospitals from 1821 to 1826. His others activities, especially teaching, affect his busy time table. His unit's recruitment is less specialized in thoracic pathologies than it was from 1816 to 1819. It is true that his "Collège of France Lessons" as his lectures, in the faculty of medicine concern all the clinical aspects. So the links between hospital activities and the second edition of his Treaty are not so strong as they were with the first one.