Letter listing for 1740–1749
- Gabrielle Émilie de Châtelet-Lomont d’Haraucourt, marquise Du Châtelet-Lomont [née Le Tonnelier de Breteuil] to Jean François de Saint-Lambert, marquis de Saint-Lambert, 20 April 1749
- Edward Young to Caroline Haviland [née Lee], 20 April 1749 [inferred existence]
- Gabrielle Émilie de Châtelet-Lomont d’Haraucourt, marquise Du Châtelet-Lomont [née Le Tonnelier de Breteuil] to Jean François de Saint-Lambert, marquis de Saint-Lambert, 21 April 1749
- David Hume to Charles Louis de Secondat, baron de Montesquieu, 21 April 1749
- Françoise Paule Huguet de Graffigny [née d’Issembourg Du Buisson d’Happoncourt] to François Antoine Devaux, 22 April 1749
- Lodovico Antonio Muratori to Cardinal Fortunato Tamburini, 23 April 1749
- Pietro Ercole Gherardi to Lodovico Antonio Muratori, 24 April 1749
- Lodovico Antonio Muratori to Nicola Tacoli, 24 April 1749
- Lodovico Antonio Muratori to Nicola Tacoli, 24 April 1749
- Voltaire [François Marie Arouet] to Johann Bernoulli, II, 24 April 1749
- Françoise Paule Huguet de Graffigny [née d’Issembourg Du Buisson d’Happoncourt] to François Antoine Devaux, 25 April 1749
- Lodovico Antonio Muratori to Cardinal Fortunato Tamburini, 25 April 1749
- Voltaire [François Marie Arouet] to Frederick II, king of Prussia [the Great], c. 25 April 1749
- Pietro Ercole Gherardi to Lodovico Antonio Muratori, 26 April 1749
- Françoise Louise Eléonore de La Tour, baronne de Warens to Jean François Hugonin, 26 April 1749