Journal of a tour in Iceland in the summer of 1809.

"In 1809 he went to Iceland to make a botanical survey for [Sir Joseph] Banks; his collections were lost in a fire at sea on the way home but with the aid of Banks’s notes from his own journey there in 1772 Hooker was able to produce an account which was published in 1811" (ODNB). Digital facsimile from Biodiversity Heritage Library at this link. There was also an issue from Yarmouth: Printed by J. Keyman, 1811, "Not Published".