DIDEROT, Denis (1713-1784). Three autograph letters signed, the first, n.p., 16 December 1776 to an unidentified correspondent (an official) writing as a former fellow student, on behalf of a surgeon of Bellevue who is being shabbily treated, 'on le renvoye le bâton blanc à la main, apres vingt ans de service', asking him to use his influence to take up the case, and referring to the warmth of his request, 'c'est l'effet d'une maladie chronique que je traine dupuis environ cinquante ans. Cette maladie consiste à ressentir la paine du malheureux, quelquefois plus vivemens que lui-même', 2 pages, 8vo; the 2nd, to Monsieur Caperonnier at the Bibliotheque Royale, n.p.. n.d., asking if he can lend him an opera by Pomone, one page, 8vo (integral address leaf, part torn away, repaired); the 3rd to Monsieur Girbal (his copyist), referring to some words which Gibral cannot decipher, ½ page, 8vo, integral address leaf (browned). (3)