Another source of botanical ambiguity and error is the circumstance of certain plants having acquired the names of others very different in their nature, but which were supposed to possess a similarity in external character; thus our POTATOE,[81] (_Solanum Tuberosum_) when it was first imported into England by the colonists in the reign of Queen Elizabeth, gained its appellation from its supposed resemblance to an esculent vegetable at that time in common use, under the name of the Sweet Potatoe (_Convolvulus Battatas_,) and which, like _Eringo Root_, had the reputation of being able to restore decayed vigour, thus Falstaff— “Let the sky rain Potatoes, hail kissing Comfits, and snow Eringoes.” _Merry Wives of Windsor, Act 5, Scene 5._ A similar instance is presented to us in the culinary vegetable well known under the name of the JERUSALEM ARTICHOKE, which derived its appellation in consequence of its flavour having been considered like that of the common artichoke; it is hardly necessary to observe that it has no botanic relation whatever to such a plant, it being an Heliotrope (_Heliotropium Tuberosum_), the epithet _Jerusalem_ is a curious corruption of the Italian term _Gira-Sole_, that is, _turn-sun_, in English, or _Heliotrope_ in Greek. This instance of verbal corruption is not solitary in medical botany; CASTOR OIL will suggest itself as another example; this oil, from its supposed efficacy in curing and assuaging the unnatural heat of the body, and in soothing the passions, was called by the French _Agnus Castus_, whence the inhabitants of St. Kitt’s in the West Indies, who were formerly blended with the French in that Island, called it _Castor_ oil. In some cases again, a plant has received a modern name, compounded of two ancient ones; it appears from Pliny that the _Assarum_ was not uncommonly confounded with the _Baccharis_; an English name was accordingly bestowed upon it, which is a curious compromise of the question, for it is a compound of both, viz. _Assara-bacca_. In some instances the most alarming mistakes have occurred from substances of a very different nature having been mentioned under similar names, _Arsenic_ for instance, has actually been inhaled,[82] together with the vapours of Frankincense, Myrrh, and those of other gums, during a paroxysm of Asthma! a practice which arose from the practitioner having confounded the Gum Juniper, or _Vernix_ of the Arabians, which was prescribed for fumigations under the name of _Sandarach_, with the Σανδαρακη of Aristotle, and which was a sulpheret of Arsenic. The gum which we know at the present day under the name of _Sanguis Draconis_, or _Dragon’s blood_, was called by the ancient Greeks Κινναβαρὶ, a term which has been incorrectly transferred to a Sulphuret of Mercury, for no other reason than because this mineral has the same red colour as the gum.