Thanks for introduction to Dr Duncan, who has been visiting. Details of a business transaction. Notes that Smith will receive a letter from [Christiaan Hendrik] Persoon. Encloses a recently published pamphlet, ["De vi vitali sanguini..." (1795)]. The "enigmatical sea-animal of the class of worms" from Linnaean collections that Smith sent Blumenbach is a 'Sabella' as described in [Johann Samuel] Schröter, "Einleitung in die Conchylienkenntniss nach Linne" (1783-1786).