The manuscript is a quatrain dedicated to Mme la Comtesse de Rochefort, deemphasizing the significance of the god Mercury in favour of his ‘voisine’. There is no trace of the correspondence between Voltaire and Marie Thérèse de Larlan de Kercadio, la comtesse de Rochefort. However, she plays the role of the Baroness de Croupillac in L’Enfant prodigue.

Frederick II asks Maupertuis to send him a complete collection of all the editions of the works of Voltaire that have been printed in Paris, London, Holland and Geneva, adding that Thiériot can help him. Frederick acknowledges that he is asking for an entire library, but states simply that he wants to have it. He asks that Maupertuis have everything bound in morocco with gilded edges, and tells him to send him the account of the disbursement. In a postscript, Frederick asks if d’Argens has shown him a letter he wrote on Voltaire’s on latest work, the Nouveaux mélanges, adding that he thinks that it will be printed in the Mercure de France.

In the letter dated 24 April 1775, Thomas writes that the ‘patriarch of Ferney’ [Voltaire] speaks at ease about envy, noting that ‘it is Apollo who speaks on the body of the serpent Pithon struck down at his feet. But the teeth of the monster are terrible, and not everyone has the arrows of the god. I wish you one of the arrows from his quiver. It is up to you to irritate the monster and to defeat him.’
In the letter dated 7 July 1775, Thomas writes that he was astonished to see his private letters printed in the Mercure as they are not suitable for the public eye. He quips that ‘Mr de Voltaire alone can have this right; all that escapes from his pen, can interest, and his praises become titles.’
In the letter dated 14 July 1778, Thomas deplores the circumstances of Voltaire’s funeral, and the prohibition of publicity and theatrical representation that followed his death.
In the letter dated 6 February 1779, he discusses the eulogy of Voltaire proposed by the academy, arguing that it must ‘awaken all the talents’ because ‘in celebrating him, one must speak his language, and verses worthy of him are the most beautiful homage.’