Papers of John Adams, volume 11
In order to keep my promise of sending you all essential news, to save time, and to spare me the sometimes intolerable task of copying the same things too many times, I decided to send my letter to Congress to you, so that you can read it, and then be kind enough to enclose it with your next letter to America.1 If this arrangement meets your approval, I will continue to do it from time to time; it would give me much relief.
I hope you are enjoying perfect health, and can send good news when you have it. Everyday I regret not having your estimable company and conversation, on your fireside.
I heard it said that the courier who arrived on the 21st with the treaty risked being stopped while passing through someplace in Hanover. He escaped the situation by speaking a few words of Russian and was therefore taken for a Russian.2
I have the honor to be with great respect and inviolable attachment, sir, your very humble and very obedient servant
This is probably the letter Dumas began on 19 Dec. 1780 and finished on 23 Jan., and which Congress received on 19 Nov. (PCC, No. 91, I, f. 483–486). Since JA's letters to the president of Congress written between 25 Nov. 1780 and 18 Jan. 1781 also arrived on 19 Nov. 1781, it seems likely that JA enclosed Dumas' letter with those letters.
Because George III was the elector of Hanover, transit of the treaty by a Dutch courier involved some risk.