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"[Plin. Nat. 27.54.] - THE ENNEAPHYLLON: TWO REMEDIES.
The enneaphyllon has nine long leaves, and is of a caustic nature. It is employed topically, but when used it is wrapped in wool to prevent it from cauterizing further than desirable, for it blisters immediately. For lumbago and sciatica it is of the greatest utility. "
(The Natural History. Pliny the Elder. John Bostock, M.D., F.R.S. H.T. Riley, Esq., B.A. London. Taylor and Francis, Red Lion Court, Fleet Street. 1855.)