Encouraged to write to Smith by "conviction of the liberality of [his] mind, and [his] readiness to assist the younger part of the community, displayed in [his] valuable works". Encloses specimen of an 'Endocarpon' of [Erik] Acharius, found on river Tyne, and identified by [Dawson] Turner as 'Endocarpon leptophyllum' Acharius and 'Lichen lectophyllus' of "English botany"; and "shields" of what Turner calls 'Parmelia turneri', accompanying 'Verrucaria amphibola' Acharius; observations.