``An Alchemists Glossary of Terms, Definitions, Formulas & Concoctions - Part 2

Dictionary Table of Contents Dictionary - Part 1 (A-H) Dictionary - Part 3 (S-Z)

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Iceland Spar (Calcite)
A particular crystal form of Calcium Carbonate (CaCO3).
Icy Butter
Antimony Chloride (SbCl3).
Igneous Fluid
a postulated Elastic Fluid sometimes used synonymously with Caloric (matter of heat), sometimes with Phlogiston (matter of fire), and sometimes as a substance with the postulated properties of both.
Another name proposed for promethium, element 61.
To soak or saturate with a liquid.
Infernal Stone
An Alkali Hydroxide (NaOH, KOH). [Not to be confused with the French term pierre infernale.]
Inflammable Air
Usually Hydrogen (H2), though the usage is not constant among Priestley, Watt, Lavoisier, or Berthollet. Sometimes Carbon Monoxide (CO).
Inflammable Air from Metals
Hydrogen (H2).
The extraction of chemical substances by soaking them in a solvent, usually water. Sometimes boiling water was poured on a mixture of substances and then allowed to cool in order to aid the extraction; but if the heat were used, the temperature could not exceed that of boiling water.
Digestion in which the heat was supplied by the sun rather than a furnace.
To thicken or condense.
Intermediate Salt of the Ley of Blood
Potassium Ferrocyanide (K4Fe(CH)6).
Intermediate Salts
Usually normal salts; occasionally acid salts.
Any reagent or reactant believed to be necessary for a reaction but which does not always appear on the product.
The process of swelling up.
An isotope of thorium produced in uranium decay, namely 230Th (half-life = 80 kyr). See Table of Isotopes.
A preparation from the root of the South American plant Cephaelis Ipecacuanha.
Iron Ochre
A mixture of silica, clay, and various Oxides of Iron. In red ochre the Oxide is simple Fe2O3; in yellow ochre it is Fe2O3.H2O.
Iron Vitriol
Ferrous Sulphate (FeSO4).
In the first half of the 18th. century a gelatinous substance extracted from the air-bladders of certain fish. Later, a synonym for sheet mica.
A black pigment prepared by the calcination of ivory in a closed vessel.

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A powder from the dried roots of the Mexican plant Exogonium purga. Used as a purgative.
James' Powder
A powder prepared by Dr. Robert James (1703-1776) that was used to reduce fevers.
The coating of an object with a very dark varnish. The original varnish came from Japan, but substitutes were later found.
Jeweler's Etchant
3g. Silver Nitrate + 3g. Nitric Acid + 3g. Mercurous Nitrate + 100cc water.
Jove (of Jove)
Tin, or some compound or alloy of Tin.
In astrological and alchemical thought, the seven heavenly bodies known to the ancients were associated with Seven Metals also known in antiquity. Jupiter was associated with Tin. [Helmont].

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The plant Salsola kali or glasswort from which, oddly enough, "mineral" alkali (Sodium Carbonate) was extracted by calcination. Also sometimes used for crude Sodium Carbonate.
Latin (and German) for Potassium, hence the symbol K.
A fine, white clay used in the manufacture of porcelain.
Impure Soda (Na2CO3) from seaweed. In Britain, the term was sometimes used for crude Sodium Carbonate from any source. Also ashes of seaweed from which Carbonates or Iodine were extracted.
Kelvin Scale
An Absolute Temperature Scale (i.e., one in which absolute zero is assigned the value zero) named after William Thomson, first (and last) Baron Kelvin of Largs, who first proposed an absolute temperature scale. One Kelvin (denoted simply K or sometimes in older sources °K) is the same size as a Celsius degree, so the normal freezing point of water is 273.15 K and the normal boiling point is 373.15 K. (See Celsius Scale, Fahrenheit Scale, Rankine Scale, Réaumur Scale.) [Kelvin].
Kermes Mineral
A natural mixture of Antimony Oxide or a mixture obtained in the laboratory by the actions of Potassium Carbonate (K2CO3) on Antimony Sulphide.
Killed Spirits
Zinc Chloride.
King's Yellow
A mixture of orpiment with white Arsenic. Also a native yellow Arsenic (III) Sulfide, As2S3 (Yellow ArsenicYellow Orpiment).
Kurrol's Salt
A Potassium pPhosphate, (KPO3)4, with ion-exchange properties.

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Lac (Laque)
A relatively thick solution of a colorant or coating.
Lac Sulphuris
See milk or Sulphur.
Latin for stone; also an alchemical term for non-volatile solids.
Lapis Calaminarus (Calamine)
Mineral form of Zinc Carbonate (ZnCO3)
Lapis Causticus
Fused Sodium or Potassium Hydroxide, NaOH, KOH.
Lapis Haematites
Hematite (Fe2O3)
Lapis Imperialis
Silver Nitrate, AgNO3.
Lapis Infernalis
Fixed vegetable alkali, I., Potassium Carbonate (K2CO3)
Lapis Lunaris
Fused Silver Nitrate, AgNO3.
Lapis Philosophorum
A mixture of fused Alum, Vitriol, Bolus, Cerussa, Camphor, Vinegar.
Lapis Ponderous
Calcium Tungstate (CaWO4)
Lapis Septicus
Potassium Hydroxide (KOH)
Lapis Serpentin
A mineral chiefly characterized by the presence of hydrous Magnesium Silicate (Mg3Si2O5(OH)4)
See Lac.
Any medicinal preparation with opium as a primary ingredient.
Laughing Gas
Nitrous Oxide, N2O.
Lead Black
Graphite, an allotrope of Carbon.
Lead Fume
Lead Oxide obtained from the flues at lead smelters.
Lead sulphide (PbS)
Lead, Red
Lead Oxide, Pb3O4 (Minium, Paris Red).
Lead White
Basic Lead Carbonate, 2PbCO3.Pb(OH)2 (Ceruse).
Ley of (Ox-) Blood
The lixiviate from the residue produced by igniting blood with potashes.
Ley of Soapboilers
Potassium Hydroxide (KOH)
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 17th. 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.[J. Davy].
Libra (Pound) Troy
See Apothecary Measures.
Light Carburetted Hydrogen
Marsh gas or methane (CH4)
Light Inflammable Air
Hydrogen (H2)
Unit of length in late 18th. century France; see Pied. [Lavoisier].
Lignum Nephriticum
Two distinct woods were known as lignium nephriticum: (1) the small Mexican tree or shrub Eysenhardtia polystacha and the large Philippine tree Pterocarpus indica. In the 16th., 17th., and early 18th. centuries, cups, powders, and dried extracts of this wood were thought to have a great medicinal powers. The infusion was flourescent.
Lignum Vitae
"Tree of Life" The wood , and sometimes the resin, of several semitropical trees, but most often referring to Guaiacum.
Filing on a metal piece to reduce it to filings. Sometimes used for simply polishing an object.
Calcium Oxide (CaO). (Burnt Lime, Calcareous Earth, Quicklime) [Dalton, Lavoisier, Priestley, Ramsay, et al.]
Lime, Carbonate of
Calcium Carbonate (CaCO3) (Mild Calcareous Earth, Chalk).
Lime, Chlorinated
See Bleaching Powder.
Lime, Milk of
A suspension of calcium hydroxide. See Milks.
Lime, Quick
Calcium Oxide (CaO) [Bacon, Black, Lavoisier, Priestley].
Lime, Slaked
A caustic substance Calcium Hydroxide, Ca(OH)2, produced by heating limestone. (Hydrated Lime, Caustic Calcareous Earth).
Calcium Carbonate (CaCO3)
Lime Water
A solution of Calcium Carbonate (CaCO3) Also a saturated aqueous solution of Calcium hHydroxide Ca(OH)2 (Liquor Calcis) [Black, Dalton, Lavoisier, Ramsay et al.]
Liquescent (Salts)
See Deliquescence.
Liquor Fumans Boyle (Spiritus Fumans Boyle)
Ammonium Polysulphide ((NH4)S2; (NH4)2S5).
Liquor Fumans Libavh (Fuming Liquor of Libavius)
Stannic Chloride (SnCl4).
Liquor of Flints
See Liquor Silicum.
Liquor Hoffman
A mixture of Ethanol and Ether.
Liquor of Liravius
See smoking spirit of Libavius.
Liquor Silicum (Liquor of Flints)
A solution of Potassium Silicate (K2 SiO3). Sometimes Used for other soluble Silcates.
Yellow Lead (II) Oxide (PbO);  Reddish-Yellow crystalline form of Lead Monoxide, formed by fusing and powdering massicot. [Marignac, Priestley].
Soft, claylike substances, such as kaolin.
A blue pigment, extracted from certain lichens. It is acid sensitive, turning red in the presence of an acid. The red form turns blue again when a base is added.
Liver of Antimony
Fused Antimony Sulfide (Sb2S3). Usually produced from the detonation of equal parts of crude Antimony and Potassium Nitrate.
Liver of Arsenic
Fused mixture of Potassium Carbonate and (white) Arsenic. May have contained some Potassium Arsenate.
Liver of Sulphur (Hepar Sulphuris)
Produced by heating Potassium Carbonate with Sulphur. Not a true compund, it is a metastable mixture of Potassium Polysulfides and Sulfate. (K2S, K2S2, K2S3, K2S4, K2S5, K2SO4).   Complex of Polysulphides of Potassium, made by fusing Potash and Sulphur. (melted Potassium Carbonate + Sulfur).
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. [Proust].
Lixivial Salts
Salts prepared by lixiviations.
Lixiviate of Mars
Possibly a tincture of Iron, of which there were many different preparations. Typically, these were solutions of salts of Iron to which rectified spirit of wine (Ethanol, (CH3CH2OH) was added .
Separation of soluble from unsoluble solid substances by soaking the mixture of solids and removing the resulting solution which contained the soluble material.
A solution produced by lixiviation. Sometimes used as a general synonym for "Solution"
Lixivium of Tartar
A solution of Potassium Carbonate (K2CO3)
Any ore.
The American tree Haematoxylon campechionum, used in dying. It produces dark shades: blacks, blues, and dark grays.
A variety of limestones.
Lunar Cornea
Fused Silver Chloride (AgCl). The soft colourless tough mass of Silver Chloride, made by heating Horn Silver until it forms a dark yellow liquid and then cooling. Described by Oswald Croll in 1608.
Lunar Caustic
Fused Silver Nitrate (AgNO3). See Moon.
Lunar Crystals
Finely divided parts of Silver Nitrate (AgNO3). In preparing these crystals great care was taken to use only the purest Silver and Nitric Acid possible.
Lunar Nitre
Silver Nitrate (AgNO3).
Potassium Hydroxide solution, KOH.

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The softening and weakening of a solid sample, even to the point of partial decomposition, by soaking it in a liquid.
Magisterium Tartari Vitriolati
Probably Potassium Sulfate (K2SO4).
Magistery of (any substance)
A precipitate of any substance, i.e., a pure form of the substance which has been separated by precipitation.
Magistery of Bismuth
Basic Bismuth Nitrate (BiNO3 . H2O); sometimes the Oxide (BiO) or even the Oxychloride (BiOCl).
Magistery of Coral
Calcium Carbonate (CaCO3).
Magistery of Sulfur
Precipitated milk of Sulphur (S).
Any substance prepared from the basic elements of the substance without impurities. A magistry was supposed to be closer to the ideal for a substance than was usual for real chemical preparations.
Magnesium Carbonate (MgCO3). [Modern Magnesia = Magnesium Oxide (MgO)]. Some chemists called Magnesium (Mg) by the name Magnesia.
Magnesia Aerata
Magnesium Carbonate (MgCO3).
Magnesia Alba
Magnesium Carbonate (MgCO3). Literally "white magnesia" was a hydrated Magnesium Carbonate, also known as mild Magnesian Earth. [Black, Scheele] 4MgCO3.Mg(OH)2.5H2O was Magnesia Alba Levis, and MgCO3.Mg(OH)2.4H2O was Magnesia Alba Ponderosa.
Magnesia Nigra
Natural Manganese Dioxide (MnO2). Literally "Black Magnesia" was the mineral pyrolusite, sometimes also called simply Magnesia or Manganese. [Scheele] Eventually Manganese became the name of the metal present in the mineral.
Magnesia Salita
Magnesium Chloride (MgCl2).
Sir Humphry Davy's name for Magnesium (Mg), the metal obtained from Magnesia Alba, proposed to avoid confusion with the metal found in Magnesia Nigra.
Magnus Salt
Tetrammineplatinum Tetrachloroplatinate, Pt(NH3)4PtCl4, named after Heinrich Gustav Magnus.
Malachite, Green
Pulverized Malachite, a basic Copper Carbonate mineral, (CuCO3 . Cu(OH)2), used as a pigment; or a green Triphenylmethane dye, C23H25N2Cl, also known as Victoria Green or Benzal Green, an acid-base indicator that changes from yellow to blue-green as the pH is raised through 1
Malic Acid
An acid extracted from apples and various other fruits. Pure Malic Acid is C4H6O5.
Barley or other suitable grains after a preparation for brewing or distilling that usually included soaking, germination, and drying.
Manganese Dioxide (MnO2). Manganese as we know it was called Reglus of Manganese.
Manganese, Black
See Magnesia Nigra.
Manganese, Green
Barium Manganate, BaMnO4.
Manganese, Red
Rhodonite, MnSiO3, a Manganese Silicate mineral, or Rhodochrosite, a Manganese Carbonate mineral, MnCO3.
Manna Mercurii
Mercurous Chloride (Hg2Cl2).
A hard, crystalline, mineral form of Calcium Carbonate (CaCO3).
Marcasita Plumbea
Antimony (Sb).
Minerals similar in appearance or properties to Iron Pyrites (FeS2). Later, a general term for Pyrites. Sometimes the term was used for Sulfides of Arsenic (As2S2, As2S3, As2S5). Mineral form of Iron Disulphide. Oxidises in moist air to Green Vitriol.
See Marzipan.
Marignac Salt
Potassium Tin (II) Sulfate, K2Sn(SO4)2, named for Jean de Marignac, who is best known for atomic weight measurements.
Marine Acid
Hydrochloric Acid solution (HCl). (Muriatic Acid, Spirit of Salt).
Marine Acid Air
Gaseous Hydrogen Chloride (HCl). [Cavendish, Lavoisier, Priestley, Scheele, et al.].
Marine Alkali
Sodium Carbonate (Na2CO3). (Common Mineral Alkali, Fossil Alkali, Soda).
Mariott's Law
Better known today as Boyle's Law, that the product of pressure and volume of a gas is constant; named for Edme Mariotte, who discovered it independently some time after Boyle. (P1V1 = P2V2)
Marl (Marle)
A loose soil of clays and Calcium Carbonate (CuCO3).
Mars (of Mars)
In astrological and alchemical thought, the seven heavenly bodies known to the ancients were associated with Seven Metals also known in antiquity. Mars was associated with Iron.
Marsh Gas
Methane (CH4).
Martial Balls
A mixture of Iron fillings (Fe) and Cream of Tartar (KHC4H4O6).
Martial Ethiops
Hydrated Ferrosoferric Oxide (Fe3O4 . xH2O).
Martial Extract
Concentrated tincture of mars. A concentrated solution, the chief component of which may have been Ferrous Hydroxide (Fe(OH)2).
Martius Yellow
Yhe Calcium Salt of Naphthalene Yellow.
A confection of pounded almonds, sugar, and other ingredients.
Yellow powder form of Lead Monoxide. PbO. Lead (II) Oxide, PbO.
Masurium, (Ma)
Another name proposed for technetium, element 43.
A vessel with a round bottom and long, slender neck. Used as part of several common types of distillation apparatus.
A solvent.
Mephitic (as adjective)
Noxious; poisonous or pestilential.
Mephitic Acid
Carbonic Acid (H2CO3).
Mephitic Air
Carbonic Acid (CO2).
Mercurius Calcinatus Per Se
Mercuric Oxide (HgO), prepared by the Calcination of Mercury [Priestley, Watt].  The substance known as Precipitated Mercury Per Se [Lavoisier, Priestley] or Red Precipitate [Priestley, Scheele] is the same substance; however, because of its different preparation (by mixing Mercury with Nitric Acid, evaporating, and heating the residual Mercuric Nitrate), the identity was not at first realized.
Merc. Calcin. Nitrat
Mercuric Nitrate (Hg(NO3)2).
Mercurius Corrosivus
Mercuric Chloride HgCl2.
Mercuric Corrosivus Ruber
Mercuric Oxide (HgO).
Mercurius Dulcis (Calomel, Mercurious Sublimatus Dulcus, Mild Mercury)
Mercurous Chloride (Hg2Cl2).
Mercurius Praecipitatus Per Se
Red Mercuric Oxide (HgO). Described by Geber.
Mercurius Praecipitatus Ruber
Mercuric Oxide (HgO).
Mercurius Solubilis Hahnemanni
Mercuric Oxide (Hg2O).
Mercurius Sublimatus Dulcis (Calomel, Mercurius Dulcis, Mild Mercury)
Mercurous Chloride (Hg2Cl2).
Mercurius Sublimatus Rubeus non Corrosivas
Mercuric Oxide (HgO).
Mercurius Vitae
Mixture of Antimony Oxychloride and Antimony Oxides (Sb2O3; Sb2O4, Sb2O5, SbOCl). In some contexts the term may mean just Antimony Oxychloride (SbOCl).
Mercurius Vitae Antimonii
Mixture of Antimony Oxychloride and Antimony Oxide (Sb2O3; Sb2O5, SbOCl).
In astrological and alchemical thought, the seven heavenly bodies known to the ancients were associated with Seven Metals also known in antiquity. Mercury was associated with Mercury (Quicksilver, hydrargyrum).
Mercury of Life
See Mercurius Vitae.
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). See Table of Isotopes.
Metallic Salt
Compound of a metal and an acid.
Metanil Yellow
The Sodium salt of 4'-Analine Azobenzenesulfonic Acid, C12H10N3O3SNa, an acid-base indicator that changes from red to yellow as the pH is raised through 1.8.
Methyl, Green
C25H30N3Cl, a Triphyenylmethane dye and acid-base indicator that changes from yellow through blue-green to colorless as the pH is raised.
Methyl, Orange
Sodium p-Dimethylaminobenzenesulfonate, C14H14O3N3SNa, an acid-base indicator that changes from red to yellow as the pH is raised through 3.8.
Methyl, Red
o-Dimethylaminoazobenzenecarboxylic Acid, C15H15O2N3, an acid-base indicator that changes from yellow to reddish purple as the pH is raised through 4.5.
Methylene Blue
3,9-Bisdimethylaminophenazothionium Chloride Trihydrate, C16H18N3SCl.3H2O, a thiazine dye and redox indicator.
Miasma (Miasmata)
A noxious or infectious subtle material (e.g., a vapor or exhalation) thought to be from decaying organic matter. Sometimes used for any unseen poisonous or infectious substance.
A mixed mineral form composed mostly of Aluminum Silicate but with silicates of other metals. Several complicated minerals are variously, and in combination, referred to as mica; e.g., biotite K(Mg, Fe)3AlFeSi3O10(OH, F)2.
Microcosmic Salt
An acid Sodium Ammonium Phosphate (NaNH4HPO4 . 4H2O), found in blood and natural waters.
Mild Alkali
Alkalies which produce effervescence with acids; i.e., Carbonates (-CO32¯)
Mild Calcareous Earth
Calcium Carbonate (CaCO3).
Mild Magnesian Earth
Magnesium Carbonate (MgCO3).
Mild Mercury
Mercurous Chloride (Hg2Cl2).
Mild Vegetable Alkali
Potassium Carbonate (K2CO3).
Mineral "milks" or magmas are aqueous suspensions.
Milk of Barium
An aqueous suspension of Barium Hydroxide, Ba(OH)2.
Milk of Bismuth
An aqueous suspension of basic Bismuth Nitrates, Bi(OH)2NO3 and/or BiOH(NO3)2.
Milk of Lime
An aqueous suspension of Calcium Hydroxide (suspension) (Ca(OH)2). [Scheele] See Lime.
Milk of Magnesia
An aqueous suspension of Magnesium Hydroxide, Mg(OH)2, especially a 7% suspension used as an antacid. See Magnesia.
Milk of Sulphur (lac sulphuris)
Finely divided white colloidal Sulfur (S) in solution. Usually the product of the reaction between a soluble sulfide and an oxidizing acid. Geber made this by adding an acid to thion hudor.
Millon's Base
(HOHg)2NH2OH, formed from a solution of Mercuric Oxide in Ammonium Chloride; named for A. N. E. Millon.
Minderer's Spirit
A solution of Ammonium Acetate (NH4C2H3O2).
Mineral Alkali
Hydrated Sodium Carbonate (Na2CO3). (Fossil Alkali, Marine Alkali, Soda)
Mineral Anodyne of Hoffman (Liquor of Hoffman)
A mixture of Ethanol and Ether (C2H5OH), (CH3CH2OCH2CH3).
Mineral Crystal (Sal Prunella)
Potassium Nitrate with a small admixture of Potassium Sulfate (HNO3; K2SO4).
Mineral, Dye
An inorganic pigment.
Mineral Blue
A blue Copper or Tungsten ore, or a mixture of Ferriferrocyanide, Fe4[Fe(CN)6]3, with Calcium or Barium Sulfate, BaSO4.
Mineral Green
Copper (II) Carbonate, CuCO3.
Mineral Purple
A reddish Iron Oxide pigment
Mineral White
A natural hydrated Calcium Sulfate
Mineral Yellow, Cassel Yellow
Lead Oxychloride, PbCl2.2PbO.
See Apothecary Measures.
Minium (Red Lead, Paris Red)
Scarlet crystalline powder Lead Tetroxide (Pb3O4).  Triplumbic Tetroxide. Formed by roasting litharge in air.  [Lavoisier, Priestley]. Minium once referred to Cinnabar (Mercuric Sulfide, HgS) as well, but now is used only for its cheif adulterant, red Lead Oxide.
A chemical union of two or more true "elements" or "principles." Later, any substance which could be resolved into constituent parts only by chemical means. Although the term has greater philosophical complexities, it was roughly equivalent to our term "compound," but the latter is not to be considered a synonym.
Mixtura Salina
Saline mixture prepared by saturating Potassium Carbonate with lemon juice and adding syrup of black currants, julep.
An exhalation or vapor of a mephitic (noxious or poisonous) gas.
Mohr's Salt
Ferrous Ammonium Sulfate (FeSO4((NH4)2SO4 . 6H2O), named for Karl Friedrich Mohr.
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.).
Native Molybdenum Sulfide (MoS2).
Monsel Salt
An Iron Sub-Sulfate, Fe4(SO4)5O.
Monthier Blue
A blue pigment, FeNH4[Fe(CN)6].
Moon (Luna)
In astrological and alchemical thought, the seven heavenly bodies known to the ancients were associated with Seven Metals also known in antiquity. The moon was associated with Silver (argentum). See Lapis Lunaris, Lunar Caustic.
Any substance which fixes or holds a colorant in the material to be dyed.
To change or destroy the normal, external form or appearance of a substance.
Mosaic Gold
Golden-yellow glistening scales of crystalline Stannic Sulfide (SnS2), made by heating a mixture of Tin filings, Sulphur and Sal Ammoniac.  Tin (IV) Sulfide, SnS2, a pigment.
Mucilagenous Matter
Any semisolid material that was soft, moist, and viscous.
Mundic (Mundick)
Iron Pyrites (FeS2). Sometimes used for other pyrites or as a general term for pyrites.
Chlorides (-Cl¯); see Muriatic Acid. [Avogadro, Gay-Lussac, Thenard, T. Thomson]
Muriate of Mercury
Mercuric Chloride.
Muriatic Acid (Acidum Salis)
Hydrochloric Acid (HCl) ( Marine Acid, Spirit of Salt); Muriatic Gas is gaseous HCl. [Black, Gay-Lussac, Prout, Scheele, Thenard, et al.]
Muriatic Ether
Probably impure Ethyl Chloride (CH3CH2Cl).
Mustard Gas
Di(chloroethyl)sulfide, (ClCH2CH2)2S, used as a chemical weapon in World War I.

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Naples Yellow or Cassel Yellow
Lead Antimoniate (Pb3(SbO4)2).  Also: An Oxychloride of Lead, made by heating litharge with Sal Ammoniac.
Any highly inflammable, volatile, naturally occurring mixture of hydrocarbons. Also could be obtained as the "lightest" fraction in the distillation of asphalts, bitumens, and petroleum.
Napthalene Yellow
Dinitro-1-naphthol, C10H5(NO2)2OH.
Naples Yellow
Lead Antimoniate, Pb3(SbO4)2, used as a yellow pigment.
Latin for Sodium, hence the symbol Na.
Natron (Natrum)
Sodium Sesquicarbonate, a naturally occurring combination of Sodium Carbonate (Na2CO3) and Sodium Bicarbonate (NaHCO3) in the ratio 1:1 (Na2CO3 . NaHCO3 . 2H2O).
Neutral Arsenical Salt of Macquer
Potassium Dihydrogen Arsenate (KH2AsO4).
Neutral Red
Dimethyldiaminotoluphenazine Hydrochloride, also known as Toluylene Red; an acid-base indicator that changes from blue to magenta as the pH is raised through 7.5 and then to orange-yellow as pH is raised through 8.
Neutral Salts
Salts resulting from the reaction of an acid and a base (hydroxide) but having no characteristics of either acid or base.
Named by the copper miners of Westphalia the 'kupfer-nickel' or false copper.
Nihil Album (sometimes just Nihil)
Flowers of Zinc, Zinc Oxide (ZnO).
Nile Blue
C20H19ON3, an analine dye and acid-base indicator that changes from yellow through blue to magenta as the pH is raised.
The element Radon, Rn, or one of its isotopes, 222Rn (half life = 3.8 d). See Emanation and Table of Isotopes.
Nitrated Earths, Metals, etc.
Nitrates (-NO3).
Nitre (Common Nitre or Niter)
Potassium Nitrate (KNO3). (Saltpeter). Black gunpowder was made from Nitre, Charcoal, and Sulfur. [Cavendish, Mayow, Priestley, Rayleigh, Watt, et al.].
Nitre, Chile
Sodium Nitrate, NaNO3.
Nitre, Mercurial
Mercuric Nitrate, Hg(NO3)2 [Scheele].
Nitre, Norwegian
Calcium Nitrate, Ca(NO3)2.
Nitre, Rough
Magnesium Chloride, MgCl2.
Nitre, Spirt of
See Spirit.
Nitre Fixed by Tartar
A mixture of nitre and tartar left after reaction between the two.
Nitre with an earthy base
Usually Calcium Nitrate (Ca(NO3)2).
Nitreum (Bergman)
Nitrous Acid (HNO2).
Nitric Acid
Nitric Acid HNO3, formerly referred to Nitrogen Dioxide, NO2 [Avogadro, Dalton, Gay-Lussac, Lavoisier et al.] or Nitrogen Pentoxide, N2O5 [Prout].
Nitro-Aerial Spirit
The hypothetical subtle substance which was though by some to be responsible for the ability to nitre to support combustion and to be a key component of detonations
Nitrous Acid
Nitrous Acid (HNO2), formerly referred to Nitric Acid, HNO3 (Aqua Fortis, Spirit of Nitre) [Lavoisier], or Nitrous Acid, HNO2, or a mixture of these acids; or one or more of the Nitrogen Oxides N2O3, NO2, N2O4, N2O5 [Avogadro, Dalton].
Nitrous Acid Vapor (Priestly)
Nitrogen Dioxide (NO2).
Nitrous Air (Priestly)
Nitric Oxide (NO)
Nitrous Ether
Ethyl Nitrite (CH3CH2NO2).
Nitrous Gas (Lavoisier)
Specifically Nitric Oxide (NO) (Nitrous Air) [Avogadro, Dalton, Gay-Lussac, T. Thomson, et al.]; or a mixture of Nitrogen Oxides such as that produced by the action of Nitric Acid on a metal in the presence of air
Nitrum Aegypticum
Sodium Carbonate (Na2CO3).
Nitrum Antimoniatum
Product containg Potassium Nitrate, Nitrite, and Antimonate.
Nitrum Commun
See commom Nitre
Nitrum Cubic
See Cubic Nitre
Nitrum Fixatum (Nitrum Fixum, Fixed Nitre)
An ofter impure preparation of Potassium Carbonate (K2CO3).
Nitrum Flammans
Ammonium Nitrate (NH4NO3). Made by Glauber.
Nitrum Regeneratum
Potassium Nitrate (KNO3).
Nitrum Saturni
Lead Nitrate (Pb(NO3)2).
Nitrum Stibnatum
Probably Anitmony Nitrate (2Sb2O3.N205).
Nitrum Sulphure Purgatum
Mixture of Potassium Nitrate (KNO3) and Potassium Sulfate (K2SO4).
Nitrum Vitriolatum
Mixture of Potassium Nitrate (KNO3) and Potassium Bisulfate (KHSO4).
Non Metals
A term used by William Cullen and his students for the following group of substances; Zinc (Zn), Anitmony (Sb), Bismuth (Bi). Arsenic (As), Platinum (Pt), Cobalt (Co), Nickel (Ni).
Nordhausen Acid (Oleum)
Fuming Sulfuric Acid. (H2SO4), i.e. a solution of Sulfur Trioxide, SO3, in concentrated (about 98%) Sulfuric Acid.

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Ochre (Ocher)
A class of mineral solids which, in powdered form, were commonly used as pigments. Their colors varied from yellow to brown, including reddish hues. Chemically, the ocheres are Iron Oxides, or mixtures of Iron Oxides, in varying states of hydration. For example red ochre is primarily Fe2O3. Silicates, Carbonates, Sulfates, etc. also were commonly present with these Oxides.
Ochre, Antimony
Stibiconite, an Antimony mineral, Sb2O3(OH)2.
Ochre, Bismuth
Bismite, Bi2O3.3H2O.
Ochre, Brown
Bogore or Bog Iron Ore, 2Fe2O3.3H2O.
Ochre, Molybdic
Molybdite, yellow Molybdenum (VI) Oxide, MoO3.
Ochre, Nickel (Nickel Bloom)
Annabergite, Ni3As2O2.8H2O, a green mineral.
Ochre, Plumbic
Brown Lead (IV) Oxide, PbO2.
Ochre, Red
Hematite, Fe2O3.
Ochre, Telluric
Yellow Tellurium (IV) Oxide, TeO2.
Ochre, Tungstic
Yellow Tungsten (VI) Oxide, WO3.
Ochre, Yellow
A mixture of powdered Iron Oxide and clay.
Cerium Oxide (CeO2).
Offa Helmonth
Potassium Carbonate (K2CO3).
Any relatively insoluble, inflammable, somewhat viscous liquid.
Oil Gas
Mixture of Methane, Carbon Monoxide, and Butlylene (CH4, CO, C4H8).
Oil of Ants
Furfural, C5H4O2.
Oil of Apples
n-Pentyl Pentanoate, C5H9CO2C5H11 (amyl valerate). Today it belongs to a group known as Esters.
Oil of Arsenic
Arsenic Trichloride (AsCl3)
Oil of Banana (Oil of Pear)
n-Pentyl Acetate, CH3CO2C5H11.
Oil of Chalk
Calcium Chloride solution (CaCl2).
Oil of Cloves
An oily substance extracted from the buds and flower stalks of the clove tree Caryophyllus aromaticus. Used as medicinal.
Oil of Cognac (Enanthic Ether)
Ethyl Hexyl Ether, C6H13OC2H5.
Oil of Dippel
The insoluble, viscous fraction from decomposed animal matter that has gone through repeated distillations.
Oil of Garlic
Allyl Sulfide, (C3H5)2S
Oil of Glonoin
Nitrogylcerin, C3H5N3O9.
Oil of Hartshorn
A crude animal oil obtained from the destructive distillation of bones
Oil of Lime
A solution of Calcium Chloride (CaCl2).
Oil of Mars
Deliquescent Anydrous Ferric Chloride.
Oil of Mirbane
Nitrobenzene, C6H5NO2.
Oil of Mustard
Allyl Isothiocyanate, C3H5NCS.
Oil of Pear (Oil of Banana)
n-Pentyl Acetate, CH3CO2C5H11.
Oil of Pineapple
Ethyl Butyrate, C3H7COOC2H5.
Oil of Rue
The oil extracted from evergreens of the genus Ruta. Used as Medicinal
Oil Sulphur
Concentrated sulfuric acid. Sometimes the term was used for Alkaline Sulphide of Ammonia (NH4)2S).
Oil of Tartar
Concentrated Potassium Carbonate solution (K2CO3).
Oil of Tartar per Deliquium
Potassuim Carbonate, which is hydroscopic, dissolved in the water which its extracts from the air.
Oil of Venus
Concentrated solution of Copper Nitrate (Cu(NO3)2.
Oil of Vitriol (Oil of Sulfur, Per Campanum)
Sulfuric Acid (H2SO4). Made by distilling Green Vitriol. Vitriolic Acid
Oil of Wine
A hypothetical component of Alcohol thought to give it its odor and inflammability
Olea Terebinthine
Olefiant Gas
Ethylene (C2H2). Also referenced as Ethene, C2H4 [Dalton, Prout, Thenard, T. Thomson, et al.]. See Dutch Oil.
Latin for oil. Also, fuming Sulfuric Acid (Nordhausen Acid).
Oleum Dulce
See Oil of Wine
Oleum Suphuris per Campanum
Sufuric Acid (H2SO4) prepared by burning Sulfur under a bell jar and later concentrating and purifying the product by heating to drive off water and sulfur dioxide.
Oleum Succini
Concentrated Succinic Acid( HOOCCH2CH2COOH).
Oleum Tartar per Demiquium
See Oil of Tartar per Deliquium
Oleum Vitriol
Oil of Vitriol
Orpiment, Red (Realgar, Red Arsenic)
Arsenic (II) Sulfide, As2S2.
Orpiment, Yellow (Auri-Pigmentum, Yellow Arsenic, King's Yellow)
Yellow ore of Arsenic. Arsenic Trisulfide (As2S3), Arsenic (III) Sulfide, As2S3.
Unit of mass in late 18th. century France; see Livre. [Lavoisier].
Oxycarburetted Hydrogen
Water gas mixture or Hydrogen (H2), Carbon Monoxide, (CO), and Carbon Dioxide (CO2).
Oxymuriatic Acid (Oxygenated Muriatic Acid)
Chlorine (Cl2). (Dephlogisticated Marine Acid); named on the belief that it was a compound of Oxygen and HCl (Muriatic Acid). [Avogadro, Berzelius, Davy, Thenard]

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Potassium Sulfate (K2SO4).
Calcium Sulfate (CuSO4).
Paris Blue
Ferric Ferrocyanide, Fe4[Fe(CN)6]3.
Paris Green
Copper (II) Acetoarsenite, Cu(C2H3O2)2.3Cu(AsO2)2.
Paris, Plaster of
Hemihydrated Calcium Sulfate, 2CaSO4.H2O.
Paris Red
Colcothar or Minium
Paris Yellow (Leipzig Yellow)
Chrome Yellow.
The operation by which Gold and Silver are separated from each other.
Patent Yellow
Lead Oxychloride, PbO.PbCl2.
Pearl Ash
The whitest impure calcined Potassium Carbonate (K2CO3) extracted from calcined plants. In a sense pearl ash is purified potash.
Pearl White
Basic Nitrate of Bismuth, Bismuth Oxychloride [BiOCl], used by Lemery as a cosmetic.
A special distillation apparatus. The condensing head had two curved tubes emerging on opposite sides. These tubes led down and entered the lower section or body of the vessel; thus, the condensed liquid ran back to the heated section where it was revaporized, giving a cyclic action. The pelican was especially effective for reactions that took place in the vapor phase.
Péligot's Salt
Potassium Chlorochromate, KCrO3Cl, named for Eugène Péligot.
Any thin saline crust that forms on a solution.
Per Campanum
Any process carried out under a solution.
Per Deliquium
A hygroscopic salt was said to "run per deliquium" when it changed from solid to liquid by extracting water from the air.
Perkin's Mauve (Violet)
See Aniline Purple.
Perlate Salt
Sodim Phosphate (Na3PO4).
Spontaneous evaporation or (less often) vaporization through heating. Also used to indicate condensation of moisture on a relatively cool body.
A medcinal which promoted perspiration.
Liquid bitumens.
A white mineral solid used in the manufacture of porcelain.
An alloy of Tin. Originally with up to one-fifth Lead, but later Bismuth and Copper were substituted for lead.
Phenol Red
Phenolsulfonphthalein, C19H14O5S, an acid-base indicator that changes from yellow to red as the pH passes through 8.
Philosopher's Wool or nix alba (white snow)
Zinc Oxide (ZnO).  Made by burning Zinc in air. Called Zinc White and used as a pigment.
Philosophical Flowers of Vitriol
Boric Acid (H3BO3).
Philosophical Foliated Earth
Potassium Acetate (KC2H3O2).
Philosophical Mercury
An alchemical term signifying the property-bearing principle of chemical activity.
Philosophical Sal Ammoniac
Ammonium Sulfate ((NH4)2SO4).
Philosphical Spirit of Nitre
Nitric Acid prepared by distilling saltpeter with Oil of Vitriol (HNO3).
Philosophical Spirit of Tartar
Potassium Hydrogen Tartrate (KHC4H4O6) distilled with wine.
Philosophical Spirit of Vitriol
Hydrochloric Acid (HCl).
Philosophical Spirit of Wine.
Spirit of wine (Alcohol) concentrated by freezing (CH2CH3OH).
Philosophical Water (Aqua Regia)
A solution of Hydrochloric and Nitric Acids, usually in ratios from 2:1 to 4:1 (HCl to HNO3).
A general term for any aqueous fraction of a distillation.
Phlogisticated Acid of Nitre
Nitrous Acid (HNO2).
Phlogisticated Acid of Vitriol
Sulphurous Acid (H2SO3).
Phlogisticated Air
Nitrogen (N2).
Phlogisticated Alkali
Potassium Ferrocyanide (K4Fe(CN)6 . 3H2O).
Phlogisticated Calx of Iron
Ferrous Oxide (FeO).
Phlogisticated Earth of Molybdaena
The solid reduction of Molybdic Acid.
Phlogisticated Manganese
Manganous Carbonate (MnCO3).
Phlogisticated Nitre
Impure Potassium Nitrite (KNO2).
Phlogisticated Nitrous Acid
Nitrous Acid (HNO2).
Phlogisticated Vitriolic Acid
Sulfurous Acid (H2SO3).
A hypothetical substance originally used to account for the property of inflammability. It later was made to carry many more properties and formed a central point for the theoretical beliefs of a central point for the theoretical beliefs of a number of 18th. century chemists. Also referenced as 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. [Cavendish, Priestley, Scheele, Watt et al.]
Phlogiston Elasticum
Hydrogen (H2).
Phosphorated Iron
Ferric Phosphate (FePO4).
Phosphorated Mercury
Mercuric Phosphate (Hg3(PO4)2).
Phosphorated Vegetable Alkali
Potassium Phosphate (K3PO4).
Sometimes used for any phosphorescent substance.
Phosphorous of Baldwin
Calcium Nitrate (Ca(NO3)2).
Phosphorous of Homberg
Calcium Chloride (CaCl2).
Phosphorous of Urine
As the name implies, a form of Phosphorous (P) extracted from urine.
Phosphuretted Hydrogen
phosphine, PH3 [Dalton].
A 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. [Lavoisier].
Pierre Infernale
Fused Silver Nitrate, AgNO3.[Not to be confused with "Infernal Stone."]
Pinch Beck
A gold colored alloy of about five parts Cooper (Cu) to one part Zinc (Zn).
Pinguious (Pinguinous)
Fatty, oily
A volume unit in late 18th. century France, equal to 2.01508 English pints, 58.145 cubic inches, or 0.953 liters. [Lavoisier]
Any semisolid plastic mixture that could be applied to a a surface and then spontaneously cured or hardened. One of the oldest plasters is a mixture of Slaked Lime (Ca(OH)2), sand, and hair. The term also was used to refer to impure Lead Oleate (Pb(C18H33O2)2).
Plaster of Paris
Calcium Sulfate Monohydrate ((CaSO4)2 . H2O).
Platinum (Pt.), or sometimes the usually impure form of Platinum found in nature that is alloyed with other exotic metals.
Plessy's Green (Arnaudon's Green)
Chromium (III) Phosphate, CrPO4, a green pigment.
Plimmer's Salt
Sodium Antimony Tartrate, Na(SbO)C4H4O6.
A lead ore, including Lead Oxide (Litharge) or Lead Sulfide (Galena); or Graphite an allotrope of Carbon (C)  (Black Lead). [Lavoisier, Priestley, Thenard]
Latin for lead, hence the symbol Pb.
Plumbum Album
Basic Lead Carbonate (2PbCO3 . Pb(OH)2). Sometimes the term was applied to basic Lead Acetate (Pb(C2H3O2) . Pb(OH)2 . H2O).
Plumbum Cinereum
Bismuth (Bi).
Plumbum Corneum (Horn Lead)
Lead Chloride (PbCl2).
Plumbum Stridens
Tin (Sn)
Pertaining to subtle, rarified, or vaporous substances such as air. In modern terms, gaseous.
Pneumatic Trough
An apparatus developed over the 18th. century from John Mayow (1641-1679) through Stephen Hales (1677-1761) to Antoine Lavoisier (1743-1794). The trough was any large pan or vat in which inverted bottles full of water could be supported. Glass tubes conducted the gases from the vessels in which they were generated outside the trough to the inverted bottle in the trough, where the gases were trapped and held.
Point of Saturation
The instant when the exact proportions of the two "saline principles" ( one from an acid, the other from a base) unite to form a perfectly neutral salt.
Flowers of Zinc (ZnO).
Crude Zinc Oxide, ZnO (Flowers of Zinc). [Lavoisier].
Ponderous Spar
Barium Sulfate (BaSO4).
Pot Ash (Potash)
Crude or purified Potassium Carbonate (K2CO3). (Vegetable Alkali, Pearl Ash) or crude Sodium Carbonate Na2CO3 leached from the ashes of plant material; or Potassium Hydroxide, KOH (Lye), or even Potassium Oxide, K2O. [Dalton, Rayleigh, T. Thomson et al.]
Unit of length in late 18th. century France; See Pied.
Powder of Algaroth
A white powder of Antimonious Oxychloride (SbOCl), made by precipitation when a solution of Butter of Antimony in spirit of salt is poured into water.
Praecipitate Per Se
Mercuric Oxide (HgO).
Praecipitatus Albus
Mercurous Chloride (Hg2Cl2).
Praecipitatus Vigonis
Mercuric Oxide (HgO).
A substance serving as intermediary to separate two other substances from each other.
Precipitate, Black
Hg2O.Hg2NH2NO3, also known as Hahnemann's mercury, a black powder used as an antisyphilitic.
Precipitate, Red
See Mercurius Calcinatus Per Se.
Precipitate, White (Sal Sapientiae, Sal Alembroth
HgNH2Cl; an insoluble white powder used in medicine as an antiparasitic.
Precipitate, Yellow
Yellow Mercury (II) Oxide, HgO.
Precipitate of Sulfur
Precipitated Milk of Sulfur (S).
The phenomenon in which a solid is formed within a solution and falls to the bottom of the vessel in which the solution was contained.
Primus Metal
See Prince Rupert's Metal
Prince Rupert's Metal (Bath Metal, Primus Metal, Princes Metal)
A Brass metal alloy in which the ratios of Copper (Cu) to Zinc (Zn) are approximately 4 to 1.
Prince's Metal
See Prince Rupert's Metal
One of the simplest forms of matter, from which other substances are formed through combinations with other principles or other combinations of principles. Although there are similarities to the modern term "element", the two are not truly synonymous.
Proximate Principles
Components obtained through the chemical analysis which themselves are compounds but presumed to be simpler than the original substance.
Prussian Blue
Ferric Ferrocyanide (Fe4[Fe(Cn)6]3). Complex salts used in inks and dyes resulting from the oxidation of the white precipitate of a solution of Iron (II) Sulfate, FeSO4, and Potassium Ferrocyanide, K4Fe(CN)6.
Prussian Acid, or Prussic Acid
Hydrocyanic Acid (HCN). [Prout].
A Cyanide, CN-, Ferricyanide, Fe(CN)63-, or Ferrocyanide, Fe(CN)64-.
Prussiate, Red
Potassium Ferricyanide, K3Fe(CN)6.
Prussiate, Yellow
Potassium Ferrocyanide, K4Fe(CN)6.3H2O.
Pulvis Algarothi
Antimonious Oxychloride (SbOCl).
Pulvis Fulminans
An explosive mixture made from Potassium Nitrate, Potasium Carbonate, and sulfur.
A light porous stone of mixed Silicates.
Pure Clay
Alumina. Aluminum Oxide (Al2O3).
Pure Ponderous Earth
Baryta. Barium Oxide. (BaO)
Any process in which one substance is rendered free, or relatively free, of other substance. Common methods included distillation, crystallization, and precipitation.
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.
Purple Crystals
Potassium Permanganate.
Mineral form of Iron Disulphide. Stable in air.Originally, any mineral which could strike sparks from steel. The term was often used to reference Iron Pyrites (FeS2). Originally any "fire-stone" from which sparks could be struck; eventually an Iron Sulfide or Iron-Copper Sulfide. [T. Thomson]
Pyroligneous Acid
Crude Acetic Acid distillate from wood (HC2H3O2). Containing Acetic Acid (CH3COOH), Methanol (CH3OH), and Acetone (CH3COCH3).
Pyroligneous Spirit
Methyl Alcohol (CH3OH).

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Quadrangular Nitre
Sodium Nitrate (NaNO3).
The process of combining Gold (Au) and Silver (Ag) in the ratio 1:3. When the combination is dissolved in Nitric Acid, the Silver is dissolved and the Gold is separated, free from impurities.
A mineral whose primary component is Silicon Dioxide (SiO2). Its color and other aspects of its appearance depended on the impurities present.
Calcium Oxide (CaO).
Mercury (Hg). Liquid Mercury metal. [Boyle, Cavendish, Priestley, Torricelli]
Quicksilver Calcined Per Se
Mercuric Oxide (HgO).
A mixture of an essential oil and alcohol.
Quintessence of Lead
Acetone (CH3COCH3).

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Rabel's Water
The liquid obtained by macerating poppy flowers in a mixture of Sulphuric Acid and alcohol for some days and then filtering.
Racemic Acid
An optically inactive form of Tartaric Acid consisting of equal quantities of optical isomers. Racemic originally referred to the origin of the acid (grapes), but now (in chemistry) refers to an optically inactive mixture of optically active isomers. [Pasteur].
(1) Individual (fundamental) particles of viscous or rigid bodies; (2) branching or filiment-like parts of a liquid mixture.
Rankine Scale
Absolute Temperature Scale (i.e., one in which absolute zero is assigned the value zero) named after the 19th. century Scottish engineer William Rankine and denoted by °R. One Rankine degree is the same size as a Fahrenheit degree, so absolute zero (-460°F) is 0°R, the normal freezing point of water (32°F) is 492°R and the normal boiling point (212°F) is 672°R. (See Celsius Scale, Fahrenheit Scale, Kelvin Scale.).
Realgar (Red Orpiment, Red Arsenic, Ruby Arsenic, Ruby Sulfur)
Red or of Arsenic, Arsenic Disulfide (As2S2). A native red or orange Arsenic (II) Sulfide, As2S2.
Réaumur Scale
Temperature scale devised in 1731 by R. A. F. Réaumur and denoted by °R. The normal freezing point of water is 0°R and the normal boiling point of water is 80°R. (See Celsius Scale, Fahrenheit Scale, Kelvin Scale.) [Lavoisier].
The vessel attached to the condensing part of a distillation apparatus in order to receive the condensed products from the distillation.
Solid waste or refuse from a chemical operation, e.g., scoria.
The purifying or refining of a substance by one or (usually) more distillations.
Red Arsenic (Realgar)
Native Arsenic Disulphide (As2S2).
Red Bole
A red clay that contained Silicates of Iron and Aluminum. Used as a red pigment and as a base for gilding.
Red Flowers of Antimony
Probably Antimony Sulfide (Sb2S5).
Red Ochre
A mineral solid approximately 95 percent red Iron Oxide (Fe2O3). An old and important pigment.
Red Precipitate
See Red Precipitate of Mercury.
Red Precipitate of Mercury
Impure Mercuric Oxide (HgO).
Red Prussiate of Potash
Potassium Ferricyanide.
Red Saunders (Red Sanders)
The wood from the tree Pterocarpus santalinus, commonly called red sandlewood. Used in dyeing.
The returning of a substance to a previous or original condition; e.g., the restoring of a metal to the metallic state from its Oxide.
Refractory Earths
Mineral substances that do not fuse under the action of fire.
A vessel at the top or head of some stills that is surrounded by or filled with cold water to condense any vapors in tubes or vessels within it.
Regenerated Marine Salt
Potassium Chloride (KCl).
Regenerated Sea Salt
Potassium Chloride (KCl).
Regenerated Tartar
Potassium Acetate (KC2H3O2). In this form, the compound was made from distilled vinegar and salt of tartar.
Reguline Caustic
Potassium Carbonate (K2CO3).
The pure form of a metal, e.g., regulus of Antimony. A metal was formerly called the regulus of the ore from which it was reduced [Scheele]; "Regulus" (without further specification) meant Regulus of Antimony (i.e., antimony in modern nomenclature). [Lavoisier]
Reinecke's Acid
Ttetrathiocyanodiammonochromic Acid, HCr(NH3)2(SCN)4.
Reinecke's Salt
An Ammonium Salt of Reinecke's acid, NH4[Cr(NH3)2(SCN)4].H2O.
Resin of Copper
Cuprous Chloride. Made by Robert Boyle in 1664 by heating Copper with corrosive sublimate.
A vessel with a long tubular neck bent down at the point where it joins the body of the vessel. Especially suited for the distillation of substances under low heat. Used by chemists and alchemists for distillation and the like. [Black, Cavendish, Lavoisier, Scheele]
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. [Black, Lavoisier].
The restoration of a metal to the metallic state from one of its compounds. Similar to, but broader in scope, than "reduction."
See Rock Alum.
Rochelle Salt (Seignette Salt)
Potassium Sodium Tartrate (KNaC4H4O6 . 4H2O), named for the French seaport La Rochelle, where the compound was prepared; also known as Seignette's salt, after the apothecary who first prepared it.
Rock Alum
Usually larger crystals or formations of Potassium Aluminum Sulfate (KAl(SO4)2 . 12H2O). Alum of this quality often was imported from Italy.
Pure, colorless, transparent, crystalline quartz occurring naturally in large prismatic crystals. Silicon Dioxide (SiO2).
Concentrated native vegetable acid. From the usual preparations, it would be primarily Citric Acid (C6H8O7).
Roman Vitriol
Copper Sulfate (CuSO4). In Britain this terms was sometimes used for Ferrous Sulfate (FeSO4).
Röntgen Rays
X-rays, named after their discoverer, Wilhelm Röntgen.
Rouge, Crocus, Colcothar
Red varieties of Ferric Oxide are formed by burning Green Vitriol in air.
Red Corundum, Al2O3.
Ruby, Blend
Red Sphalerite, Zinc Sulfide, ZnS
Ruby, Copper
Cuprite, Copper (I) Oxide, Cu2O.
Russian Pot Ash
Potassium Carbonate (K2CO3).
Rust of Copper
See Verdigris.