When I use a word . . . The languages of medicines—chemical names

Languages

The definition of a [natural] language in the Oxford English Dictionary (OED)1 is “The system of spoken or written communication used by a particular country, people, community, etc., typically consisting of words used within a regular grammatical and syntactic structure.” A good clear definition, although I rather prefer the less rigorous but more succinct definition postulated by the US linguistics expert Leonard Bloomfield (1887–1949) in 1926: “the totality of utterances that can be made in a speech-community.”2 Bloomfield further defined an utterance as “an act of speech” and a speech-community as “[a community within which] successive utterances are alike or partly alike.” So there it is—a language. Humans have about 5000 of them, give or take 1000—they’re hard to enumerate.

Of course there are other kinds of languages. For instance, computer languages. Well over 1000 of them, from A.NET to Z++.3

Then there are the specialised languages espoused by the members of groups such as trades and professions. Medicine, for example, has its own language, which, like a foreign natural language, may be unintelligible to those outside the profession, especially when its users decline into jargon, slang, colloquialisms, and cant.4

The languages of medicines

When we come to talk about the aspects of the language of medicine dealing with medicines, the names they have and the science surrounding them, we have to start learning more than one new language.

As I have described elsewhere,5 a medicine can have up to four different types of names:

● a unique chemical name;

● generic names, one or more of them;

● brand names, often several of them;

● slang names, generally a whole host of them.

Let’s begin with the chemical names.

The 18th century: Méthode de nomenclature chimique

The earliest attempt at systematically naming chemicals came from 18th century French chemists, Guyton de Morveau, Antoine-Laurent Lavoisier, Claude Louis Berthollet, and Antoine François Fourcroy, who, in 1787, published a volume titled Méthode de nomenclature chimique, under the aegis of l’Académie des Sciences.6 Their work required the protection of the academy because it arose from Lavoisier’s controversial antiphlogistic theory.

The antiphlogistic theory, expounded by Lavoisier, was originally published in Mémoires de l'Académie des Sciences in 1777, here as translated by M P Crosland7:

1. In every combustion there is disengagement of the matter of fire or of light.

2. A body can burn only in pure air.

3. There is no destruction or decomposition of pure air and the increase in weight of the body burnt is exactly equal to the weight of air destroyed or decomposed.

4. The body burnt changes into an acid by addition of the substance that increases its weight.

5. Pure air is a compound of the matter of fire or of light with a base. In combustion the burning body removes the base, which it attracts more strongly than does the matter of heat, and sets free the combined matter of heat, which appears as flame, heat, and light.

In 1775 Joseph Priestley had given the name “dephlogisticated air” to what Lavoisier called pure air. Lavoisier called it “oxygène,” because it generated acids.

The Méthode began with an essay by Lavoisier, “Sur la nècessité de réformer & de perfectionner la nomenclature de la Chimie.” A short essay by de Morveau, “Sur le développement des principes de la Nomenclature méthodique,” was then followed by a description of the various sections in the book:

1. Des Substances qui se rapprochent le plus de l'état de simplicité.

2. Des Bases acidifiables ou principes radicaux des acides.

3. Des Substances métalliques.

4. Des Terres.

5. Des Alkalis.

After an appendix, “Contenant la nomenclature de quelques substances composées qui se combinent quelquefois à la manière des corps simple,” it was Fourcroy’s turn to contribute, in his case an essay titled “Pour servir à l'explication du Tableau de Nomenclature,” in which he described the contents of the table’s six columns. The table followed, succeeded in turn by a long list of chemical synonyms, showing how previous names were to be replaced by the authors’ proposed names. The list started with “Acete ammoniacal,” the proposed names for which were “Acétite ammoniacal” or “Acétite d’ammoniaque.” The list ended with “Zinc.”

Finally, commentaries by other authors, members of the academy, followed. A table of contents completed the work, 314 pages in all. An English translation by James St John was published in London in 1788 under the title Method of Chymical Nomenclature.

The 19th century: Swedish and German chemistry and international meetings

In the first half of the 19th century, the Swedish chemist Baron Jöns Jacob Berzelius (1779–1848) and the German chemists Justus von Liebig (1803–73) and Friedrich Wöhler (1800–82) took chemical nomenclature further, naming more and more organic compounds. Berzelius used the term “organic” to designate compounds that contained the four elements carbon, hydrogen, oxygen, and nitrogen, because they were constituents of living organisms. Liebig and Wöhler discovered, among other things, that cyanic acid and fulminic acid were isomers of each other, and that certain groups of atoms, radicals as we would now call them, could act as substituents in different compounds,8 important when pharmaceutical chemists came to exploring structure-activity relationships.

In 1860 the German organic chemist August Kekulé, best known for discovering the structure of benzene, organised a meeting to discuss the nomenclature of organic chemicals, and later meetings culminated in the founding of an International Commission for the Reform of Chemical Nomenclature in 1889. Three years later, 34 leading chemists from nine European countries met and agreed on what came to be known as the Geneva Rules for nomenclature. In particular, they introduced principles to be used in naming aliphatic compounds:

1. the name of the longest chain is taken as the parent name;

2. the presence of a functional or characteristic group of atoms is indicated by a suffix.

The 20th century

An International Association of Chemical Societies was founded in 1911, with the intentions, among other things, of standardising atomic weights, physical constants, and the nomenclatures of organic and inorganic chemistry. However, its work was prevented by World War I. A postwar international initiative was then launched in 1919, with the founding of the International Union of Chemistry, which, in 1947, was renamed The International Union of Pure and Applied Chemistry (IUPAC). The union appointed three commissions, tasked with reforming the chemical nomenclatures of organic chemistry, inorganic chemistry, and biological chemistry.

Since then, at various times IUPAC has published sets of definitive rules relating to the nomenclature of different compounds, for example, organosilicon compounds (1949), hydrocarbons and fundamental heterocyclic systems (1957), and characteristic groups containing carbon, hydrogen, oxygen, nitrogen, halogen, sulphur, selenium, and/or tellurium (1965).9

Meanwhile, in 1907, the American Chemical Society started to publish Chemical Abstracts, and in 1911 formed a Committee on Nomenclature, Spelling, and Pronunciation. The Chemical Abstracts Service (CAS) publishes bibliographical information on articles related to chemistry gleaned from many sources, including journals, books, technical reports, theses and dissertations, conference proceedings, and patents. It publishes details of over 200 million organic and inorganic substances, including alloys, coordination compounds, minerals, mixtures, polymers, and salts, and nearly 70 million protein and nucleic acid sequences.10

The 21st century

Today IUPAC combines the languages of chemical nomenclatures with computer language in the form of machine-readable chemical identifiers.11 Uniform international chemical nomenclature ensures that everyone uses the same terminology to describe chemical compounds, simplifying worldwide trade in chemicals. In many cases the chemical names of medicines are also relevant to formulation of their generic names.

Further reading

Van Tiggelen B, Fauque D (editors). Special IUPAC100 – A Glance at The Union History. Chem Int 2019; 41(3): 1-58. https://www.degruyter.com/journal/key/ci/41/3/html.

Fox RB, Powell WH. Nomenclature of Organic Compounds: Principles and Practice. 2nd edition. American Chemical Society and Oxford University Press, 2001.

Hellwich KH, Hartshorn RM, Yerin A, Damhus T, Hutton AT. Brief guide to the nomenclature of organic chemistry. 2020. https://iupac.org/wp-content/uploads/2021/06/Organic-Brief-Guide-brochure_v1.1_June2021.pdf.

Favre HA, Powell WH, Moss GP. Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. IUPAC Blue Book. Royal Society of Chemistry Publishing. Version 3, 6 December 2023. https://iupac.qmul.ac.uk/BlueBook/PDF.

Crosland MP. Historical Studies in the Language of Chemistry. New York: Dover Publications Inc, 1978.