Unpublished letter and extract, on artificial freezing of seawater from Mignonneau to [Sir Joseph Banks] Letter from Mignonneau, Commissaire des Gardes du Corps du Roi [Superintendent of the King's Bodyguards], regarding artifical freezing of seawater, which he believes could be beneficial to navigators, maritime commerce, and society in general. Followed by a typescript copy of the Journal de Paris, number 54, 23 February 1789, pages 243-245, containing a similar article written by Mignonneau. Subject: Chemistry Addressed to the President of the Royal Society [Sir Joseph Banks]. 1789-1792