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!
THE PROGRESS OF BOTANICAL SCIENCE.
It has been just stated, that we have derived from botanical science a philosophical language which enables us to describe the structure and habits of any plant, with a luminous brevity and an unerring perspicuity; but we are moreover indebted to botany for another service no less important to the successful investigation of the Materia Medica,—that of throwing into well defined groups, those plants which possess obvious natural affinities, and which will be found at the same time to present certain medicinal analogies; indeed, as a general rule, we may admit the axiom, “Quæ genere conveniunt, virtute conveniunt.”[[85]]
The Umbelliferæ which grow on dry ground are aromatic, whilst the aquatic species are among the most deadly poisons. The Cruciform plants are aromatic and acrid in their nature, containing essential oils, (hence the peculiar smell of cabbage-water, &c.) which are obtainable by distillation; and Linnæus asserts that “among all the Leguminous or Papilionaceous tribe there is no deleterious plant to be found:” this however is not exactly true. Some of the individuals in these natural orders, although very nearly related, do nevertheless possess various, and even opposite qualities; in the leguminous tribe above mentioned, which is as consistent as any one we possess, we have the Cytisus Laburnum, the seeds of which are violently emetic, and those of Lathyrus Sativus, which have been supposed at Florence to soften the bones and cause death.
In the subdivision of a genus there is often a remarkable difference in the properties of the species; there are, for instance, Solanums, Lettuces, Cucumbers, and Mushrooms, both esculent and poisonous. The Digitalis or Foxglove, and the Verbascum, or common Mullein of our fields, are included in the same Natural family, and yet the one is as active, as the other is mild in its effects; the plants of the natural family of Contortæ abound with a highly acrid milky juice, but Dr. Afzelius met with a shrub of this order at Sierra Leone, the milk of whose fruit was so sweet, as well as copious, as to be used instead of cream for tea; this is certainly what no one could have guessed from analogy. The same individual will vary from culture or other circumstances, as much as any two plants which have no botanic affinity; the Chamomile, Anthemis Nobilis, with which we are well acquainted, may have its whole disk changed by cultivation, to ligulate white florets, destitute of medicinal properties. But, what is more embarrassing, the different parts of the same plant have often very different powers; a fact which is beautifully exemplified in the Podophyllum Peltatum, or May Apple, the leaves of which are poisonous, the root powerfully cathartic, and the fruit agreeably esculent; so the leaves of the Jatropa Manihot are employed as a common esculent, while its root secretes a most virulent poison; but we need not seek further for an example than the fruit of the Lemon, the juice of which is acid, its seeds bitter, and its rind aromatic; in some instances it happens that the energy of a plant is concentrated in one particular part, and that all the rest is absolutely inert; thus, the root of the Convolvulus Scammonia, is the only portion of that plant which possesses any medicinal quality;[[86]] and the tree which yields the drastic Camboge, presents at the same time an esculent fruit, which is eaten by the natives with as much impunity as the orange; yet, notwithstanding all these difficulties, botany is capable of furnishing us with analogies which will lead to important conclusions with respect to the medicinal properties of different vegetables.