Engaged Richard Clarke of Apothecaries Hall in making further enquiries into "Balsam of Guatemala" and "'Myrospermum [falcictem]'", after ascertaining that balsam of tolu will not mix with alcohol to answer the puposes alluded to by Dr Luxunasa [Spanish doctor]. Encloses a copy of a letter from Richard Clarke, dated 25 Feb 1817, relating his findings from his enquiries, including the production methods, believes the balsam described by Dr Luxunasa relates more to balsam of Peru, comments on prescriptions and uses.