Apologises for not replying to L'Héritier's letter sooner, has been in country at [Richard] Salisbury's and at Oxford with Sir Joseph Banks and [Jonas] Dryander looking over [John] Sibthorp's plants and drawings, which are "very fine" and will raise Sibthorp's name from "botanical infamy to very high botanical honour". Thanks for 'Sida' specimens: his 'S. paniculata' "certainly right", has not yet found 'S. arborea' owing to confusion of young Linnaeus' herbarium, remarks on 'S. americana', and L'Héritier's 'S. ricinoides', 'S. aphyllantha', and 'S. cistiflora' appear to be new.