The Internet Archive has a preservation copy of this work in our general collections.
J. W. Sullivan. "Letter from J. W. Sullivan, Esq., on the subject of the accompanying Observations. Addressed to J. D. Hooker, Esq., M.D., F.R.S., F.L.S." Journal of the Proceedings of the Linnean Society of London Botany (1859) 11-12