Archaic Chemical Terms

Introduction and Part I (A-B)

Go to Part II (C-F), Part III (G-L), Part IV (M-R), or Part V (S-Z).

See also:

This glossary makes no claims for completeness or originality. I began to compile the following list mainly of terms I came across in the course of reading and posting the papers listed in the classic papers section of this site. I have expanded it to include formulas and structures for some common acid-base indicators and vitamins, as well as some other interesting non-systematic chemical terms.

I intended it mainly for my own use or as a teaching tool. As a result, it lacks the polish and the painstaking acknowledgement of sources of a scholarly work. I hope it is, nonetheless, useful. It will continue to grow as I add more papers and better cross-reference the ones I have already posted.

I have tried to cross-reference entries. Terms in parentheses () are usually linked cross-references within the glossary. Names in brackets [] are scientists in whose work the term appears (perhaps in translation), not necessarily (and usually not) those who coined the term. Many of these names have links to papers posted at this site. Use your browser's search function to find the glossed term in such a paper. The notation et al. means that there are additional papers at this site that contain the term.

Finally a partial list of sources follows:

Thanks to Peter Morris of the Science Museum, London, for comments and entries.

acid of ...

actinium ... See table of isotopes.

ad siccum: to dryness, as in evaporation to dryness. [Scheele]

aether: ether.

aethyle: ethyl.

air: formerly a general term for any gas (elastic fluid). [Black, Cavendish, Priestley]

alabamine (Ab): a name proposed for element 85 (astatine) in a report of detection of the element whose validity was ultimately not recognized.

alcohol sulphuris: carbon disulfide, CS2; not an alcohol at all, but a volatile liquid that contains sulfur.

alembroth, salt of: a double chloride of mercury and ammonium, Hg2(NH4)2Cl4.H2O; see white precipitate [Lavoisier]

algaroth, powder of: antimony oxychloride, SbOCl, an emetic named after its inventor, a Vittorio Algarotti. [Lavoisier]

alizarin: 1,2-dihydroxyanthraquinone, C14H8O4, a red dye long extracted from Rubia tinctorium (madder), synthetically prepared from anthracene in the 19th century. Click here for structures.

alkahest: a term invented by Paracelsus to denote a universal solvent. [Boyle]

alkali: a basic substance. Caustic alkalis were usually hydroxides, while mild alkalis were carbonates. (See alkaline air, fossil alkali, marine alkali, mineral alkali, vegetable alkali, volatile alkali.)

alum: originally potassium aluminum sulfate, KAl(SO4)2.12H2O; more recently the term also includes salts in which sodium or ammonium substitute for potassium. [Black, Lavoisier]

amyl: derives from amylum, starch. Some terms (amylase, amylose, amylo-pectin) are still directly related to starch. The following terms come from starch-derived amyl alcohols:

aniline purple: mauveine, C27H24N4, the first aniline dye, 1856 (Perkin's mauve).

antimony ...

apothecary measures: weight and fluid (volume) measurements used in preparing medicines. They included ... aqua: literally water (Latin). In addition to terms denoting a condition or source or water (such as aqua tepida, warm water, or aqua nivialis, water from snow), some aqua terms denote aqueous solutions: argentum: Latin for silver, hence the symbol Ag; argentum vivum, literally "living silver", is native mercury [Pliny]

Arnaudon's green: chromium(III) phosphate, CrPO4, a green pigment; also Plessy's green.


atom: does not necessarily correspond to the modern picture of the ultimate particle of an element. Dalton, for example, meant something more along the lines of "ultimate particle of a substance"; to him the smallest unit of a chemical compound was a compound atom (molecule in modern terminology), while the smallest particle of a chemical element was a simple atom (now just atom, although several of Dalton's simple atoms turned out to be molecules of elements, such as O2). (See molecule.)

aurum: Latin for gold, hence the symbol Au; aurum fulminans (fulminating gold): gold hydrazide, AuHNNH2, an olive-green powder that can explode on concussion [Black, Scheele]

azote or azotic air: nitrogen, N2 (phlogisticated air; see also mephitic air), named because it did not support respiration and was therefore "lifeless". Azote is still the French word for this element. [Dalton 1 & 2, Lavoisier, Prout, T. Thomson]

baker's salt: ammonium carbonate, (NH4)2CO3.

barilla: impure sodium carbonate extracted from soap-wort. [Rey]

barium white: barium sulfate, BaSO4.

baryta and barytes: were both used for the earth from which barium was eventually isolated, namely barium oxide, BaO. [Dalton, Lavoisier, Ramsay, et al.]. Barytes can also refer to barite, a barium sulfate (BaSO4) mineral also known as heavy spar. Baryta can also refer to barium hydroxide (caustic baryta) or its hydrate. Barytium is an older name for barium [Pasteur, Prout].

benzine: ligroin or petroleum ether [Rayleigh]; sometimes benzene, C6H6

Bezoar (or Bezoar stone or Bezoardicum minerale): a counter-poison or antidote, especially a stony calculus from an animal's stomach. [Mayow]

bitter ...

bittern: waste solution of magnesium salts and bromides from the preparation of salt from sea-water by evaporation

black ash: impure sodium carbonate mixed with unburnt carbon (hence "black") and incombustible mineral residue

bleaching powder: formed by passing chlorine gas over dry calcium hydroxide, hence also called chlorinated lime. When dry the substance is mainly calcium oxychloride, CaOCl2; after absorbing moisture, it becomes a mixture of calcium chloride and hypochlorite, CaCl2 and Ca(OCl)2

blue stone: a native crystalline copper sulfate, CuSO4.5H2O.

bone ash: an impure calcium phosphate

bone black: an impure animal charcoal prepared from bones and blood

brevium: an isotope of protactinium produced in uranium decay, namely 234Pa (half-life = 1.6 min) [Fajans 1913]

brimstone: sulfur, S. [Boyle]


bromphenol... bromthymol blue: dibromothymolsulfonphthalein, C27H38Br2O5S, an acid-base indicator that changes from yellow to blue as the pH rises through 6.8.

brunswick green: a basic copper oxychloride, CuOCl.Cu(OH)2, or a green copper carbonate.

butter: In addition to its still current meanings of a low-melting vegetable fat or a high milk-fat foodstuff, a butter could be a soft substance such as an inorganic chloride. Butter of antimony was antimony(III) trichloride, SbCl3; butter of arsenic was arsenic trichloride, AsCl3; butter of tin was a hydrate of tin tetrachloride SnCl4.5H2O; and butter of zinc was zinc chloride, ZnCl2. [J. Davy, Lavoisier]

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