Venetz picked up on and developed ideas about puzzling aspects of glaciation before his better-known friend and colleague Charpentier, whom he helped to persuade. They were in the habit of meeting and discussing ideas, as they did when Agassiz (and Schimper) came to stay with Charpentier in 1836; it was these two younger men who developed a full theory of glaciation and of a widespread ice-age.
Wedgwood was briefly Nicholson’s employer, then (along with Boulton) a colleague in a London scientific society. Davy, Dalton and Berzelius were among contributors to Nicholson’s pioneering popular scientific journal. Carlisle was a friend of his, collaborating in the discovery of electrolysis; Godwin another friend. Volta met Nicholson on a visit to England, and acknowledged his influence. Koenig consulted Nicholson in his role as patent agent about his own invention of a high-speed printing press, featuring an undeveloped idea of Nicholson’s. Hazlitt simply recorded that he’d had an interesting conversation with him.
The interesting but largely obscure Boulanger was a regular member of d’Holbach’s salon. He wrote articles for Diderot and d’Alembert’s Encyclopédie; Diderot and d’Holbach published his works posthumously. His letters to Helvetius (a friend), either initialled or signed pseudonymously, were long thought to be from a better-known associate, Voltaire for example attributing them to Diderot.
Fresnel (the ‘s’ is silent) was Biot’s protégé. Arago collaborated with him on the polarisation of light, and used Fresnel’s work on wave theory to take revenge on Biot for sabotaging his own earlier work. Poisson’s work proved Fresnel right, but to Poisson’s own embarrassment, since he’d been sure Fresnel was wrong and was personally antipathetic to him. Fresnel collaborated with his close friend Ampère on research in electro-magnetism, and corresponded with Young, who was also interested in wave theory. Prosper Mérimée was his young cousin: it is unclear whether they crossed paths meaningfully.
He met Duchamp and Roussel through his chess obsession, and founded a science-writers’ group with de Broglie. Queneau and he were both pataphysicians, and formed Oulipo initially as a spin-off. Berge, Arnaud, Roubaud, Perec and Bénabou all became Oulipians. The last three were initially shocked at what the infirm Le Lionnais charged them for round-table dinners, but grew warmer, Perec spending several days dusting and sorting his books. He sniffed out Freymann, who published books on aspects of mathematics and other interesting subjects that no-one else would, and introduced Queneau to him.