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It has been already stated that we are to a great degree ignorant of the Simples used by the ancient Physicians; we are often quite unable to determine what the plants are of which Dioscorides treats. It does not appear that out of the 700 plants of which his Materia Medica consists, that more than 400 are correctly ascertained; and yet no labour has been spared to clear the subject of its difficulties; Cullen even laments that so much pains should have been bestowed upon so barren an occasion.^[76] The early history of botany presents us with such a chaos of nomenclature, that it must have been impossible for the herbarist and physician to have communicated their mutual lights; every one was occupied with disputes upon words and names, and every useful inquiry was suspended, from an inability to decide what plant each author intended; thus, for instance, the Herba Britannica of Dioscorides and Pliny, so celebrated for the cure of the soldiers of Julius Cæsar on the Rhine, of a disease called ‘Scelotyrbe’, and supposed to resemble our sea scurvy, remains quite unknown, notwithstanding the labours of our most intelligent commentators.^[77] It seems also very doubtful whether the plant which we denominate Hemlock was the poison usually administered at the Athenian executions,^[78] and which deprived Socrates and Phocion of life. Pliny informs us that the word Cicuta, amongst the ancients, was not indicative of any particular species of plant, but of vegetable poisons in general; this is a circumstance to which I am particularly anxious to fix your attention; it is by no means uncommon to find a word which is used to express general characters, subsequently become the name of a specific substance in which such characters are predominant; and we shall find that some important anomalies in nomenclature may be thus explained. The term ‘Αρσενικον,’ from which the word Arsenic is derived, was an ancient epithet, applied to those natural substances which possessed strong and acrimonious properties, and as the poisonous quality of arsenic was found to be remarkably powerful, the term was especially applied to Orpiment, the form in which this metal more usually occurred. So the term Verbena (quasi Hebena) originally denoted all those herbs that were held sacred on account of their being employed in the rites of sacrifice, as we learn from the poets;^[79] but as one herb was usually adopted upon these occasions, the word Verbena came to denote that particular herb only, and it is transmitted to us to this day under the same title, viz. Verbena, or Vervain, and indeed until lately it enjoyed the medical reputation which its sacred origin conferred upon it, for it was worn suspended around the neck as an amulet. Vitriol, in the original application of the word, denoted any crystalline body with a certain degree of transparency (Vitrum); it is hardly necessary to observe that the term is now appropriated to a particular species: in the same manner, Bark, which is a general term, is applied to express one genus, and by way of eminence, it has the article, The, prefixed, as The Bark: the same observation will apply to the word Opium, which in its primitive sense signifies any juice (οπος Succus) while it now only denotes one species, viz. that of the Poppy. So again, Elaterium was used by Hippocrates, to signify various internal applications, especially purgatives of a violent and drastic nature (from the word ‘Ελαυνω,’ agito, moveo, stimulo), but by succeeding authors it was exclusively applied to denote the active matter which subsides from the juice of the wild cucumber. The word Fecula, again, originally meant to imply any substance which was derived by spontaneous subsidence from a liquid, (from fæx, the grounds or settlement of any liquor); afterwards it was applied to Starch, which is deposited in this manner by agitating the flour of wheat in water; and lastly, it has been applied to a peculiar vegetable principle, which like starch^[80] is insoluble in cold, but completely soluble in boiling water, with which it forms a gelatinous solution; this indefinite meaning of the word fecula has created numerous mistakes in pharmaceutic chemistry; Elaterium, for instance, is said to be a fecula, and in the original sense of the word it is properly so called, inasmuch as it is procured from a vegetable juice by spontaneous subsidence, but in the limited and modern acceptation of the term, it conveys an erroneous idea; for instead of the active principle of the juice residing in fecula, it is a peculiar proximate principle, sui generis, to which I have ventured to bestow the name of Elatin. For the same reason, much doubt and obscurity involve the meaning of the word Extract, because it is applied generally to any substance obtained by the evaporation of a vegetable solution, and specifically to a peculiar proximate principle, possessed of certain characters, by which it is distinguished from every other elementary body—See Extracta. On the other hand, we find that many words which were originally only used to denote particular substances, have, at length, become subservient to the expression of General Characters; thus the term Alkali, in its originally sense, signified that particular residuum which was alone obtained by lixiviating the ashes of the plant named Kali, but the word is now so generalized that it denotes any body possessed of a certain number of definite properties.

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.

The advanced state of Botanical Science will now prevent the recurrence of those doubts and difficulties which have formerly embarrassed the history of vegetable remedies, by furnishing a strictly philosophical language, independent of all theory, and founded upon natural structure, and therefore necessarily beyond the controul of opinion; while the advancement of chemical knowledge, by enabling us better to distinguish and identify the different substances we employ, will also materially assist in preventing the confusion which has formerly oppressed us. At the same time, I am unwilling to join in the commendations so liberally bestowed upon our chemical nomenclature; nay, I am disposed to consider it as a matter of regret that the names of our medicinal compounds should have any relation to their chemical composition, for in the present unsettled state of this science, such a language must necessarily convey theory instead of truth, and opinions rather than facts; in short, it places us at the mercy and disposal of every new hypothesis, which may lay our boasted fabric in ruins, and in its place raise another superstructure, equally frail in its materials and ephemeral in its duration: thus Corrosive Sublimate was a muriate of Mercury, or an oxy-muriate, until Sir H. Davy established his new theory of chlorine, and then it became a bi-chloride; at some future period, Chlorine will be found to be a compound, and then it must have another name; for the same reason the term Calomel,^[83] is surely to be preferred to sub-muriate, or Chloride. Tartarized Antimony, again, has been called by our nomenclatural reformers the Tartrate of Antimony and Potass; but is it a triple compound? Gay Lussac thinks not, and considers it as a combination, in which Cream of Tartar acts the part of a simple acid.

Again,—we have only to revert to the nomenclature of the Salts in our Materia Medica to discover the actual change in meaning which the same word has undergone in a very few years. It was originally understood that the term Sub, when prefixed to the generic name of a Salt, indicated the presence of certain qualities depending upon an excess of base; but now, forsooth, the term has reference only to atomic composition, without any regard to qualities.^[84] That salt alone being acknowledged as a true Sub-salt, in which there is less than one atom of acid to each atom of base; thus our “Sub-carbonate of Soda,” is no longer considered a Sub-salt, for the reason above stated; and notwithstanding the predominance of its alkaline characters, it is known to chemists by the appellation of Carbonate of soda. It is far from my intention to question the propriety of these changes, I only maintain that, amidst such chemical doubts, the Pharmaceutist is the last person who should become arbiter; let him await the issue in unobtrusive silence, and take care that the language of Pharmacy partakes of the same neutrality.

Such was the feeling of the Committee appointed by the College for the revision of the late London Pharmacopœia, and it sufficiently explains why the nomenclature of the alkaline salts has been left unchanged in the present edition of that work.

The French, in their new Codex, are absurdly extravagant in their application of chemical nomenclature; thus, the sub-carbonate of potass is called by them sub-deuto-carbonas potassii. The first part of this quadruple name indicates the comparative quantity of acid in the salt, the second that of oxygen contained in the base, the thud announces the acid, and the fourth the basis of the base!