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).
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.
- James Bryant Conant, ed., Harvard Case Histories in Experimental Science, vol. 1 (Cambridge, MA: Harvard, 1957)
- Maurice Crosland, Historical Studies in the Language of Chemistry (Cambridge, MA: Harvard, 1962).
- W. E. Flood, The Dictionary of Chemical Names (New York: Philosophical Library, 1963)
- Julius Grant, Hackh's Chemical Dictionary, 3rd ed. (Philadelphia: Blakiston, 1944)
- Oxford English Dictionary (Oxford: Oxford, 1971)
- Frederick Soddy, "Radioactivity", Chemical Society Annual Reports 10, 262-88 (1913)
acid of ...
- ... air or aerial acid: carbon dioxide, CO2, which forms carbonic acid in aqueous solution [Scheele]
- ... amber: succinic acid, HOOCCH2CH2COOH
- ... ants: formic acid
- ... apples: malic acid
- ... lemon: citric acid
- ... milk: lactic acid
- ... salt: hydrochloric acid, HCl (acidum salis, marine acid, muriatic acid, spirit of salt). [Scheele]
- ... sugar: oxalic acid, (COOH)2.
actinium ... See table of isotopes.
- ... C: an isotope of bismuth produced in actinium decay, namely 211Bi (half-life = 2 min) [Soddy]
- ... D: an isotope of thallium produced in actinium decay, namely 207Tl (half-life = 5 min). [Soddy 1 & 2]
- ... emanation (actinon, see emanation): an isotope of radon produced in actinium decay, namely 219Rn (half life = 4 s).
ad siccum: to dryness, as in evaporation to dryness. [Scheele]
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.
- alkaline air: ammonia gas, NH3; see spirit of hartshorn, volatile alkali. [Priestley]
- dephlogisticated air: oxygen, O2 [Cavendish, Ingenhousz, Lavoisier 1 & 2, Priestley 1 & 2, Watt]; also known as pure air, [Lavoisier, Priestley, Watt] or vital air [Lavoisier]. See phlogiston.
- fire air: oxygen [Scheele]
- fixed air: carbon dioxide, CO2 (carbonic acid, calcareous gas). [Black, Cavendish, Priestley et al.]. (aer fixus) Scheele]
- fluor acid air: silicon tetrafluoride, SiF4 [Priestley].
- hepatic air: hydrogen sulfide, H2S (sulphuretted hydrogen)
- inflammable air: This term was applied to hydrogen, H2, once it was recognized as a distinct air; it was also used as a descriptive term for flammable gases or gas mixtures more generally. [Cavendish, Franklin, Priestley, Watt et al.]
- mephitic air: nitrogen, N2 (azote, phlogisticated air), or carbon dioxide, CO2 (carbonic acid, fixed air, mephitic acid) [Lavoisier]
- nitrous air: nitric oxide, NO (nitrous gas) [Cavendish, Lavoisier, Priestley 1 & 2]
- phlogisticated air: nitrogen, N2 (azote) [Cavendish, Lavoisier, Priestley 1 & 2, Watt]
- phlogisticated nitrous air: nitrous oxide, N2O (laughing gas); see nitrous air. [Priestley]
- pure air: dephlogisticated air.
- urinous air: (aer urinosa) ammonia; see alkaline air.
- vital air: dephlogisticated air.
- vitriolic acid air: sulfur dioxide (SO2). [Priestley] See vitriolic acid.
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]
- ... black: naphtharazine, 5,8-dihydroxy-1,4-naphthoquinone, C10H6O4, a black dye
- ... blue (anthracene blue): a dihydroxyanthraquinone quinoline, C17H9O4
- ... bordeaux (... brown): 1,2,3-trihydroxyanthraquinone, C14H8O5, a dye derived from anthraquinone
- ... red: alizarin sodium sulfonate, NaC14H7O7S, the sodium salt of the sulfonic acid of alizarin; an acid-base indicator that changes from red to yellow as the pH is raised through 5.5
- ... yellow: sodium p-nitraniline salicylate, C13H10NO5, an acid-base indicator that changes from yellow to purple as the pH is raised through 11.1
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).
- amyl: a pentyl radical or substituent, C5H11-.
- amylene: pentene, C5H10, usually 1-pentene or 2-pentene; isoamylene is one of the isomers of 2-methyl-2-butene.
- amyl hydrate: an amyl (i.e., pentyl) alcohol
apothecary measures: weight and fluid (volume) measurements used in preparing medicines. They included ...
- ... black: antimony(III) sulfide, Sb2S3, a grey-black powder.
- ... bloom (also ... white): antimony(III) oxide, Sb2O3
- ... butter: See butter.
- ... glance: stibnite, a native antimony(III) sulfide. (See glance.)
- ... flowers (also ... red, ... vermillion): antimony(III) oxysulfide, Sb2O3.Sb2S3, containing some SbOS2. See other flowers.
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:
- dram (drachm): unit of weight equal to 3.888 g. [Black]
- fluid dram (drachm): unit of volume equal to 3.55 mL (60 minims). [Scheele]
- minim: unit of volume equal to 0.0616 mL
- pound (libra) Troy: unit of weight equal to 373.2 g
- scruple: unit of weight equal to 1.296 g. [Black]
argentum: Latin for silver, hence the symbol Ag; argentum vivum, literally "living silver", is native mercury [Pliny]
- aqua fortis: nitric acid, HNO3, literally "strong water". See nitrous acid, spirit of nitre. [Bacon, Black, Scheele]
- aqua regia or aqua regis: literally "water of the king", a mixture of concentrated nitric and hydrochloric acids capable of dissolving the "royal metal" gold. [Bacon, Scheele]
- aqua vitae: literally, "water of life"; concentrated aqueous ethanol, C2H5OH, typically prepared by distilling wine [Arnald of Villanova] (spirit of wine)
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]
- ... salt: magnesium sulfate, MgSO4.7H2O (Epsom salts)
- ... spar: dolomite (magnesium calcium carbonate) [Klaproth]
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]
- ... green: C21H14Br4O5S, an acid-base indicator that changes from yellow to blue as the pH is raised through 5
- ... purple: C21H16Br2O5S, an acid-base indicator that changes from yellow to purple as the pH is raised through 6
bromthymol blue: dibromothymolsulfonphthalein, C27H38Br2O5S, an acid-base indicator that changes from yellow to blue as the pH rises through 6.8.
- ... blue: tetrabromophenolsulphonphthalein, C19H10Br4O5S, an acid-base indicator that changes color from yellow to blue as the pH rises through 3.8
- ... red: dibromophenolsulphonphthalein, C19H12Br2O5S, an acid-base indicator that changes color from yellow to red as the pH rises through 6.5
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) chloride, 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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