Sending a species of 'Hyoscyamus' for Smith to examine. Makes observations of his own, believing it may be variety of 'Hyoscyamus niger' found by [John] Martyn [(1699-1768) botanist] in 1729 and not noticed since by any English writer. Comments on it being found outside Paris by Tournefort, abortive attempts to grow it in gardens, and location the specimen was collected from.

Sending fifth and sixth volumes of his "Systema vegetabilium" for Smith. Smith will become the "British botanical Socrates" with his "English Flora", extravagantly compliments Smith. His son has translated Smith's "Grammar of Botany" into German. Horror at the "deplorable confusion of philosophical & theological systems hovering now on the continent". [Franz Wilhelm] Sieber's travels and antiquarian and botanical collections. Count Sternberg has received remainder of [Thaddäus] Haenke's herbarium. [Carl Friedrich Philipp von] Martius publishing descriptions of species he collected in Brazil, starting with the palms. Forthcoming botanical publications by Lehman, Reichenbach, and [Augustin Pyramus] Decandolle's "Prodromus".

Error in his recently published third volume of "Midland Flora"; found that his 'Trichia rubiformis' is not the 'T. rubiformis' of Persoon's "Synopsis methodica fungorum"; difficulty of making correct references from descriptions alone, for which reason he has preserved every specimen he could; observations on Persoon's species, confirmed in another Persoon work ["Tentamen Disp. Meth. Fungorum"]. Wishes he had seen [Robert Kaye] Greville's "Monograph of the Genus 'Erineum'" before publishing his third volume.

Asks Smith's opinion of [Samuel Frederick] Gray's work ["A natural arrangement of British plants" (1821)].