This is a collection of drafts of letters written by Dutour to Abbé Jean Antoine Nollet. Dutour describes his various experiments on the influence of flame on electricity, as well as with luminous barometers. There is information relative to eighteenth-century scientific apparatus, as well as to contemporary scientists, such as Giambatista Beccaria, Francois de Cisternay Du fay, Dortous de Mairan, Petrus von Musschenbroek, and René Antoine Ferchault de Réaumur.

The papers of the Italian natural philosopher and electrician, Giambatista Beccaria (1716-1781) contain letters to Benjamin Franklin, Joseph Banks, Laura Bassi, Gian Francesco Cigna, and others on a variety of scientific topics, including atmospheric and terrestrial electricity, the aurora borealis, earthquakes, meteorology, and phosphorescence. In addition to Beccaria's epistolary essays, the collection includes several journals of meteorological observations and notes for Giovanni Eandi's biography of Beccaria.