Autograph letter signed : London, to R. W. Elliston, 1798 March 21.

Thanking his nephew for a side of lamb: "We have eaten part, sent some to your Father & Mother, and reserved some yet to be eaten; the sample already devoured was as delicate as any I ever tasted"; offering his assistance: "If I can at any time serve you or contribute to your happiness in any way, you may command me, as far as my means extend"; saying that they are leaving London in a few days to settle in Bedfordshire, "the lean [sic] of our house here expiring at Lady day, and the air of this place, if it may be called air, not agreeing with either of us"; wishing Elliston a good journey to Edinburgh; sending news of his son John King Martyn: "Whilst you are giving moral lectures at Bath & Bristol, your Cousin John is reading lectures in Mathematics at Cambridge. Who would have thought half a dozen years ago, when you were playing the fool together in Park Prospect, that you would have been each now instructing mankind"; telling Elliston that his father wrote to William Elliston (his brother and R. W. Elliston's uncle), asking for money: "The Dr replies, that he has advanced to you his allowance to Midsummer 1798, and that you & he agreed that all supplies to your Father were to pass thro' you. I dare say you think with me that it would have been better if he had not made any such application"; sending love from himself and his wife Martha to Elliston, his wife Elizabeth and their daughter Eliza, "of whom we hear wonders from every body."