An autograph letter signed 'Le Bn de Humboldt', addressed to 'Monsieur le Duc' (likely Nicola Filomarino, duca della Torre), dated 'Paris, le 27 Mars 1820'
Humboldt writes to introduce the geologist Alexandre Brongniart, remembering with gratitude the assistance rendered by le Duc to himself and his friends and collaborators, [Louis Joseph] Gay-Lussac and [Christian Leopold von] Buch. He hopes that M. Brongniart, 'l'homme célèbre', who wishes to visit Vesuvius and the lava flows of Ischia..... More