Autograph letter signed.

4to. 1 page. An invitation to spend some time among friends at the countryside: "I have a few very pleasant friends of both sexes, amongst which, I hope, will be Mr and Mrs De Loutherbourg - to take their tea and pass their evening of tomorrow. Can you join us? a very hearty welcome will await you, and a little countrified trip may tend to your recovery. Let me know, and by way of re-introducing my new book and rectifying the misnomer without awkwardness suppose you insert the enclosed [.]". - Pratt worked successfully as an actor at Drury Lane Theatre where the mentioned Philip James de Loutherbourg was earning his living as a scenery and costume designer. Loutherbourg also taught at the Royal Academy and is noted for having introduced William Turner to fine oil painting. Loutherbourg and his wife took up faith-healing after an encounter with the notorious Alessandro Cagliostro. One Mary Pratt published a pamphlet entitled "A List of a Few Cures performed by Mr and Mrs De Loutherbourg, of Hammersmith Terrace, without Medicine [.]" (1789), in which the author claimed that the Loutherbourgs had cured 2000 people in half a year. Samuel Pratt met Benjamin Franklin in 1777, who later would lend him money in a serious financial crisis. - Includes a collector's note. Traces of old mounting on the verso; some brownstaining.