The Alchemy web site on

Alchemical and archaic chemistry terms

Part II (L-Z)

href=""> with some later additions by Gleb Butuzov
Partial list of sources:
Julius Grant, Chemical Dictionary, 3rd ed. (Philadelphia: Blakiston, 1944)
James Bryant Conant, ed., Harvard Case Histories in Experimental Science, vol. 1 (Cambridge, MA: Harvard, 1957)
W. E. Flood, The Dictionary of Chemical Names (New York: Philosophical Library, 1963)
Frederick Soddy, "Radioactivity", Chemical Society Annual Reports 10, 262-88 (1913)

Go to Part I (A-K)

lead fume. Lead oxide obtained from the flues at lead smelters.

Libavius, fuming liquor of (spiritus fumans Libavii): tin tetrachloride (SnCl4), which fumes because it is hydrolyzed by moisture in the air to stannic oxide. First prepared at the beginning of the seventeenth century by the German chemist Andreas Libavius. When mixed with one-third of its weight of water, it forms a hydrate formerly called butter of tin.

ligne: Unit of length in late 18th-century France; see pied.

lime: calcium oxide (CaO, calcareous earth, quicklime). Carbonate of lime was calcium carbonate (CaCO3, mild calcareous earth, chalk), and slaked lime calcium hydroxide (Ca(OH)2, caustic calcareous earth).

lime-water: a saturated aqueous solution of calcium hydroxide (Ca(OH)2).

litharge: lead (II) oxide (PbO).

litharge. Reddish-yellow crystalline form of lead monoxide, formed by fusing and powdering massicot.

liver of sulphur. Complex of polysulphides of potassium, made by fusing potash and sulphur.

livre: Unit of mass in the late 18th-century France: 1 livre (Paris pound) = 16 onces; 1 once (Paris ounce) = 8 gros; 1 gros = 72 grains. In modern units, the livre is equivalent to 489 grams or about 1.08 pounds in the "English" system still commonly used in the United States.

logwood: haematoxylin

luna cornea. The soft colourless tough mass of silver chloride, made by heating horn silver till it forms a dark yellow liquid and then cooling. Described by Oswald Croll in 1608.

lunar caustic, lapis infernalis. Silver nitrate.

lye: potassium hydroxide solution (KOH)

magnesia etc.: Magnesia alba (literally "white magnesia") was magnesium carbonate (MgCO3), also known as mild magnesian earth. The metal present in this compound is magnesium, but was named magnium by Davy to avoid confusion with another magnesia. Magnesia nigra (literally "black magnesia") was the mineral pyrolusite, natural manganese dioxide (MnO2), sometimes also called simply magnesia or manganese. Eventually manganese became the name of the metal present in the mineral.

manganese: See magnesia etc. Also corruption of ancient magnesia-- which however didn't refer to manganese, but either to talc or to magnets.

marine acid: hydrogen chloride solution (HCl, acidum salis, muriatic acid, spirit of salt). Gaseous HCl was marine acid air.

marine alkali: sodium carbonate (common mineral alkali, fossil alkali, soda)

mephitic air: nitrogen (N2, azote, phlogisticated air) or carbon dioxide (CO2, carbonic acid, fixed air, mephitic acid).

mercurius calcinatus per se: mercuric oxide (HgO, precipitated mercury per se, red precipitate).

mercurius praecipitatus. Red mercuric oxide. Described by Geber.

mercury of life, Paracelsus's name for one of his curative concoctions; he may have used mercury in its preparation, but it was actually antimony trichloride.

mesothorium: There were two mesothoriums produced in thorium decay. Mesothorium I is an isotope of radium, namely 228Ra (half-life = 5.8 y); mesothorium II is an isotope of actinium, namely 228Ac (half-life = 6 hr)

milk of sulphur (lac sulphuris). White colloidal sulphur. Geber made this by adding an acid to thion hudor.

mineral alkali, common: hydrated sodium carbonate (fossil alkali, marine alkali, soda)

minium: a lead oxide (Pb3O4, red lead). Formed by roasting litharge in air. Scarlet crystalline powder.

molecule: does not necessarily correspond to the modern conception of two or more atoms chemically bound together. Avogadro, for example, meant something like "ultimate particle of a substance"; his elementary molecule corresponds to a modern atom and his composite molecule to a modern molecule. (See atom.)

molybdena (molybdenum disulphide)-- the name derives from Greek molübdaina 'lead'-- it seems that miners saw lead everywhere.

mosaic gold. Golden-yellow glistening scales of crystalline stannic sulphide, made by heating a mixture of tin filings, sulphur and sal ammoniac.

muriate: chloride; see muriatic acid.

muriatic acid: hydrochloric acid (HCl, acidum salis, marine acid, spirit of salt); muriatic gas is gaseous HCl.

Naples yellow, or Cassel yellow. An oxychloride of lead, made by heating litharge with sal ammoniac.

narcotic salt of vitriol (boric acid)-- made from (green) vitriol, another name for iron sulphate, not to be confused with copper sulphate, or blue vitriol.

natron. Native sodium carbonate.

nickel. Named by the copper miners of Westphalia the 'kupfer-nickel' or false copper.

nitre or niter: potassium nitrate (KNO3, saltpeter). Black gunpowder was made from nitre, charcoal, and sulfur.

nitric acid: nitrogen dioxide (NO2) or nitrogen pentoxide (N2O5).

nitrous acid: nitric acid (HNO3, aqua fortis, spirit of nitre) or nitrous acid (HNO2) or a mixture of these acids; or one or more of the nitrogen oxides N2O3, NO2, N2O4, N2O5

nitrous air: nitric oxide (NO, nitrous gas).

nitrum flammans. Ammonium nitrate made by Glauber.

nitrous gas: specifically nitric oxide (NO, nitrous air) or a mixture of nitrogen oxides such as that produced by the action of nitric acid on a metal in the presence of air.

oil of vitriol or oil of sulfur per campanum or spirit of vitriol (spiritus vitrioli): sulfuric acid (H2SO4, vitriolic acid). Made by distilling green vitriol.

olefiant gas: ethene (C2H4). See Dutch oil.

once: Unit of mass in late 18th-century France; see livre.

orpiment; auri-pigmentum. Yellow ore of arsenic. Arsenic trisulphide.

oxygen, Lavoisier's name for oxygen, so called because he thought it was the formative principle of acids (Greek oxüs). Close but no cigar-- hydrogen is. One of Lavoisier's few mistakes. Scheele's name, fire air, would have been better.

oxymuriatic acid: chlorine (Cl2, dephlogisticated marine acid); named on the belief that it was a compound of oxygen and HCl (muriatic acid). It was Lavoisier's name for a gas derived from muriatic (hydrochloric) acid. He obviously saw it as a compound of oxygen.

pearl ash: potassium carbonate (K2CO3)

pearl white. Basic nitrate of bismuth, used by Lemery as a cosmetic.

philosophers' wool, or nix alba (white snow). Zinc oxide made by burning zinc in air. Called Zinc White and used as a pigment.

phlogisticated air: nitrogen (N2, azote).

phlogisticated nitrous air: nitrous oxide (N2O); see nitrous air.

phlogiston: a hypothetical elastic fluid which was seen as a metalizing and combustible principle. Metals were seen as the result of combining calces with phlogiston; smelting expelled the phlogiston. In combustion, phlogiston leaves the combustible body to combine with air or saturate air. The theory of phlogiston is associated with Stahl.

pied: Unit of length in late 18th-century France: 1 pied (Paris foot) = 12 pouces; 1 pouce (Paris inch) = 12 lignes. In modern units, the pied is equivalent to 0.325 meters or about 1.07 feet in the "English" system still commonly used in the United States.

pinte: volume unit in late 18th-century France, equal to 2.01508 English pints, 58.145 cubic inches, or 0.953 liters.

plaster of paris: calcium sulfate (Ca(SO4)2.H2O)

plumbago: a lead ore, including lead oxide (litharge) or lead sulfide (galena); or graphite (black lead). Sometimes confused with black lead .

pompholix: crude zinc oxide (ZnO, flowers of zinc).

potash: crude or purified potassium carbonate (K2CO3, vegetable alkali, pearl ash) or crude sodium carbonate leached from the ashes of plant material; or potassium hydroxide (KOH, lye) or even potassium oxide (K2O).

pouce: Unit of length in late 18th-century France; see pied.

powder of Algaroth. A white powder of antimonious oxychloride, made by precipitation when a solution of butter of antimony in spirit of salt is poured into water.

precipitated mercury per se or precipitate per se: mercuric oxide (HgO, mercurius calcinatus per se, red precipitate).

prussic acid: hydrocyanic acid (HCN).

pure air: oxygen (O2, dephlogisticated air, vital air).

purple of Cassius. Made by Andreas Cassius in 1685 by precipitating a mixture of gold, stannous and stannic chlorides, with alkali. Used for colouring glass.

pyrite or pyrites: originally any "fire-stone" from which sparks could be struck; eventually an iron sulfide or iron-copper sulfide. Stable in air.

pyroligneous acid: distillate from wood, containing acetic acid, methanol, and acetone

quicklime: calcium oxide (CaO, calcareous earth, lime).

quicksilver: liquid mercury metal.

radioactinium: a radioactive isotope of thorium produced in actinium decay, namely 227Th (half life = 19 d).

radio-elements: For occurrences before 1913 (i.e., before the concept of isotopy), radioisotopes is often a more appropriate modern term.

radiolead: a radioactive isotope of lead produced in uranium decay, namely 210Pb (half life = 21 y). Also radium D.

radiotellurium: An isotope of polonium produced in uranium decay, namely 210Po (half life = 140 d). [Markwald] Also called radium F.

radiothorium: an isotope of thorium produced in thorium decay, namely 228Th (half-life = 1.9 y).

realgar. red ore of arsenic. Arsenic disulphide.

red lead: a lead oxide (Pb3O4, minium).

red precipitate: mercuric oxide (HgO, mercurius calcinatus per se, precipitated mercury per se). One way of preparing red precipitate was by mixing mercury with nitric acid, evaporating, and heating the residual mercuric nitrate. Since precipitation from nitric acid was a different method of preparation than calcination, the author did not necessarily know that the product was the same in both cases, so the author may not regard red precipitate as synonymous with mercurius calcinatus per se.

regulus: A metal was formerly called the regulus of the ore from which it was reduced; "regulus" (without further specification) meant regulus of antimony (i.e., antimony in modern nomenclature). A regulus ('little king') was the heavy substance that sank to the bottom of your crucible. 'Antimony' then referred to kohl (antimony trisulphide), regulus of antimony thus referred to the pure metal isolated from kohl-- what we now call antimony.

resin of copper. Cuprous chloride. Made by R. Boyle in 1664 by heating copper with corrosive sublimate.

retort: a container with a long tubular neck used by chemists and alchemists for distillation and the like.

reverberatory furnace: a furnace constructed so that a sample placed within it is heated from above as well as from the fire beneath it. For example, the furnace may have a top which reflects heat on the sample from the fire below it.

rouge, crocus, colcothar. Red varieties of ferric oxide are formed by burning green vitriol in air.

saccharum saturni: sugar of lead

sal ammoniac: ammonium chloride (NH4Cl). Named so because it was made from camel dung from the Temple of Jupiter Ammon in Egypt.

sal commune: common salt, i.e., sodium chloride (NaCl).

sal enixum: potassium sulfate (K2SO4)

sal mirabilis: sodium sulfate (Na2SO4.10H2O, Glauber's salt)

saltpeter or saltpetre: potassium nitrate (KNO3, nitre).

scruple: unit of apothecary weight equal to 1.296 g.

siliceous earth: silicon dioxide (SiO2).

slaked lime. Calcium hydroxide.

soda: sodium carbonate (Na2CO3, washing soda) or sodium hydrogen carbonate (NaHCO3, baking soda. Caustic soda was sodium hydroxide (NaOH). See also fossil alkali, marine alkali, common mineral alkali. Soda ash. Sodium carbonate formed by burning plants growing on the sea shore.

Spanish white: bismuth oxychloride (BiOCl) or oxynitrate (BiONO3)

spirit (spiritus): an essence or extract that can be prepared from another substance as by distillation

spirit of hartshorn: ammonia (NH3) or its aqueous solution (acqueous ammonia)(formerly prepared from animal horns or hooves); see alkaline air, volatile alkali. A perfectly straightforward name; it was distilled from harts' horns! The same substance derived from another and less attractive process was called volatile salt of urine.

spirit of nitre: nitric acid (HNO3, aqua fortis, nitrous acid).

spirit of salt (spiritus salis): hydrochloric acid (HCl, acidum salis, marine acid, muriatic acid).

spirit of vitriol (spiritus vitrioli): See oil of vitriol.

spirit of wine (spiritus vini): concentrated aqueous ethanol (C2H5OH), typically prepared by distilling wine; see aqua vitae.

spiritus fumans. Stannic chloride, discovered by Libavius in 1605, through distilling tin with corrosive sublimate.

sugar of lead (saccharum saturni: lead acetate (Pb(CH3CO)2)

stibnite. Antimony trisulphide. Grey mineral ore of antimony.

sugar of lead. Lead acetate, Made by dissolving lead oxide in vinegar.

sulphuret: sulfide (hepar).

sulphuretted hydrogen: hydrogen sulfide (H2S, hepatic air).

sulphuric acid: sulfur trioxide (SO3).

sulphurous acid or sulphurous gas: sulfur dioxide (SO2).

tartar or tartar of wine: potassium hydrogen tartrate (KHC4H4O6), cream of tartar (cremor tartari) when purified into small white crystals. Tartar emetic is potassium antimonyl tartrate. Oil of tartar: a saturated solution of potassium carbonate (K2CO3); salt of tartar: solid potassium carbonate.

Thion hudor (Zosimus refers to this as the 'divine water' or 'the bile of the serpent'). A deep reddish-yellow liquid made by boiling flowers of sulphur with slaked lime.

tin salt. Hydrated stannous chloride.

trona: natural sodium carbonate (Na2CO3.NaHCO3)

turbith mineral (or turpeth): basic sulfate of mercury, HgSO4.2HgO.

turpeth mineral. A hydrolysed form of mercuric sulphate. Yellow crystalline powder, described by Basil Valentine.

vegetable alkali: crude or purified potassium carbonate (K2CO3, pearl ash). Sometimes specified as mild vegetable alkali or fixed vegetable alkali.

venetian white. Mixture of equal parts of white lead and barium sulphate.

verdigris. Cupric carbonate.

vital air: oxygen (O2, dephlogisticated air, pure air).

vitriol: a sulfate, especially iron sulfate. Blue vitriol was copper sulfate (CuSO4.5H2O), green vitriol was iron (II) sulfate (FeSO4.7H2O, copperas), and white vitriol was zinc sulfate (ZnSO4.7H2O).

vitriolic acid: sulfuric acid (H2SO4, oil of vitriol). Vitriolic acid air (and sometimes vitriolic acid) was sulfur dioxide (SO2).

volatile alkali: aqueous ammonia (NH3); see alkaline air, spirit of hartshorn. Concrete volatile alkali refers to ammonium carbonate ((NH4)2CO3).

white arsenic. Arsenious oxide. Made from arsenical soot from the roasting ovens, purified by sublimation.

white lead: basic lead carbonate (2PbCO3.Pb(OH)2)

wood-ash or potash. Potassium carbonate made from the ashes of burnt wood.

zaffre. Impure cobalt arsenate, left after roasting cobalt ore.

Go to Part I (A-K)of the Alchemical and archaic chemistry terms