A resin produced by an insect (Coccus Laccae, or Laccifer lacca Kerr). It is used to make shellac. Also a red dye extracted from the resin. See also Cochineal.

Web sites:
Getty Research Institute, Art and Architecture Thesaurus, "Lac (resin)" Web Link
Getty Research Institute, Art and Architecture Thesaurus, "Lac (colorant)" Web Link

See also Florentine lake, red lake.

A pigment made by precipitating the coloring material onto a ground. Recommended grounds include alum, clay, eggshells and blanc fixe (barium sulfate).

Mayer, 1957: 36.

Web sites:
Getty Research Institute, Art and Architecture Thesaurus Web Link

Lalande, Joseph-Jérôme Lefrançais de (b. 1732, Bourg en Bresse (Ain); d. 1807, Paris)
French astronomer.

Lalande was a prolific writer who published not only about astronomy but also about navigation, mathematics, practical arts, and travel.

Academy of Sciences
Académie de marine
Bureau des longitudes

Relevant Publications:
L'art de faire le maroquin ([Paris], [1766]).
L'art du tanneur ([Paris], 1764).

Michaud, 1966: 22:603–13; DSB, 1970–80: 7: 579–82.

Lambert, Johann Heinrich (b. 1728, Mulhouse; d. 1777, Berlin)
German physicist and mathematician.

Lambert, a largely self-taught mathematician, was born in Mulhouse (Alsace). After a peripatetic early adulthood that included a decade as tutor he obtained a position with the Berlin Academy in 1765. He remained there for the rest of his life, presenting more than 150 papers to different classes of the Academy on philosophy, logic, semantics, instrument design, surveying, the construction of useful mathematical tables.

Lambert's more important research, according to others, concerned the measurement of light (photometry) and mathematical proofs that pi is an irrational number.

Akademie der Wissenschaften zu Göttingen (1757)
Berlin Academy (1765)
Swiss Scientific Society (Basel)

Relevant Publications:
Die Freye Perspektive . . . (Zurich, 1759).
Photometria (Augsburg, 1760).
Beschreibung einer mit dem Calauschen Wachse ausgemalten Farbenpyramide. . . (Berlin, 1772).
Pyrometrie oder vom Maasse des Feuers und der Wärme (Berlin, 1779).

DSB, 1970–80: Christoph J. Schriba, Vol p595–600; Michaud 1854–65: 23:46–51; Gray & Tilling, 1978.

Web sites:
History of Mathematics Archive, St. Andrews "Johann Heinrich Lambert" Web Link
The Color Museum, "Johann Heinrich Lambert's Color System" Web Link

Lastman, Pieter P. (1583–1633)
Dutch history painter and draftsman.

Lastman was best known for having been a teacher of Rembrandt.

Jacques-Fabien Gautier suggested that he had experimented with color engravings.

Grove Art Online: B.P.J. Broos, "Pieter (Pietersz.) Lastman."

Lavoisier, Antoine-Laurent (b. 1743, Paris; d. 1794, Paris)
French chemist, theoretical chemist and public servant.

Lavoisier was educated at the Collège des Quatre Nations, and ultimately took a degree in law. An interest in the sciences led him to study of mathematics, astronomy, chemistry, geology and botany. He won, in 1766, a medal from the Academy of Sciences for an essay on lighting the streets of Paris. He was elected to the Paris Academy of Sciences in 1768; in that same year he became an assistant to one of the farmers-general of the revenue. He held other administrative positions outside of his work at the Academy throughout his life.

Lavoisier's contributions to the Academy frequently concerned analysis (of such things as diamonds, water, and gases) and the creation of a systematic system of description. He is known for his role in the "new chemistry:" the change from the three- or four-element, qualitative understanding of matter and its combination, to the quantifiable system based on such concepts as heat, mass, and combination.

Paris Academy of Sciences

Relevant Publications:
Traité élémentaire de chimie (Paris, 1789).
Méthode de nomenclature chimique (Paris, 1787) (with Guyton de Morveau, Berthollet and Fourcroy).

DSB, 1970–80: 8: 66–91; AdS: Dossier biographique, "Lavoisier."

Web sites:
Panopticon Lavoisier Web Link
Chemical Heritage Society, "Lavoisier" Web Link
Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy, "A Dictionary of the New Chymical Nomenclature" Carmen Giunta, Classic Chemistry Web Link

Le Blon, Jacob Christoph (b. 1667, Frankfurt am Main; d. 1741, Paris)
German-born engraver, experimenter, inventor and writer.

Le Blon was the son of a family of printers and booksellers who specialized in travel books. Le Blon himself lived a somewhat nomadic existence throughout his life, leaving Frankfurt to study in Rome (probably with Carlo Maratta), and later Zurich; working in Amsterdam then London and finally Paris.

Most biographers agree that Le Blon began to work on his three color printing technique while living in Amsterdam in the early eighteenth century. His relationship to the scientific community there, and its role in the development of his ideas has not yet been thoroughly explored. In any event, Le Blon visited London in 1710, and moved there permanently about 1718. About two years later he established his first firm to create color-printed pictures, but the process was too expensive and it failed. He later tried to establish a false-tapestry weaving firm, for which he drew upon a friendship with Sir Richard Manningham, and others. This failed too and bankrupted him. He moved to France some years later and established a print-works but again he was unable to make it a success before he died.

His notable works included copies of Titian, Maratta and Van Dyck.

Relevant Publications:
Coloritto (London, 1725).
Le Beau Ideal (London, 1732).

Grove Art Online: Ad Stijnman "Jacob Christoph Le Blon"; Lilien, 1985; Portalis and Béraldi, 1880:2.2: "Le Blon"; Burch and Gamble, 1910: "Jacob Christoph Le Blon."

Le Brun, Charles (b. 1619, Paris; d. 1690 Paris)
French painter, designer and administrator.

Le Brun was the son of a sculptor who showed a considerable talent for painting from an early age. In 1645, on returning to Paris after several years in Rome, he was named painter-in-ordinary to the King. During this time, he became the pre-eminent decorative painter and decorator in France, taking on projects as diverse as arranging entertainments, overseeing the layout of gardens, and planning tapestries.
In 1664 Louis XIV confirmed Le Brun's position as First Painter to the King and he was assigned such tasks as oversight of all royal building projects, supervision of the royal painting collection, chancellorship of the Academy of Painting and Sculpture, management of the royal tapestry and furnishings manufactures at Gobelins, and, ultimately, the transformation of the Versailles palace.

Grove Art Online: Claire Constans, "Charles Le Brun."

Web sites:
Getty Museum, "Charles Le Brun" Web Link

Le Pileur d'Apligny, Placide Auguste (Fl. 1750–75)
French administrator and author.

Le Pileur d'Apligny, was the maître des requêts for the King's council. He is closely linked to the history of indienne manufacture in Paris. He was involved in a manufacture established in 1759. More important perhaps are his books on dyeing cotton, on improvement to dyeing an on color and color production.

Relevant Publications:
L'art de la teinture des fils et étoffes de coton. . . (Paris, 1776).
Traité des couleurs matérielles et de la maniere de colorer relativement aux différens arts et métiers (Paris, 1779).
Essai sur les moyens de perfectionner l'art de la teinture: et observations sur quelques matières qui y sont propres (Paris, 1770).

Pinault et al 1987: 149.

Web sites:
José Luis Caivano, "Chronological Bibliography on Color Theory," [29 November 2004] Web Link

Le Roy, Jean Baptiste (b. 1720, Paris; d. 1800, Paris)
French physicist with an interest in electrostatics.

As a member of the Academy of Sciences, Le Roy was often called to adjudicate submissions to that society. His own interest was electricity. Le Roy contributed to the Encyclopédie several articles about scientific instruments.

Paris Academy of Sciences
Royal Society of London
American Philosophical Society

Michaud, 1966: 24:260; Hahn, 1971: 69; DSB, 1970–80:8:255–6.

Web sites:
Institute and Museum of the History of Science, Online Museum Biographies, "Jean-Baptiste Le Roy" Web Link

Le Vieil, Pierre (1708–1772)
French glass painter.

Le Vieil's family was originally from Normandy but his father (who had glazed the chapel at Versailles) had settled in Paris, where Pierre was born. Le Vieil studied at the Collège de Sainte-Barbe and the Collège de la Marche, On leaving school he had planned to take holy orders but abandoned them to work in the family trade.

Le Vieil was responsible for the stained and painted glass windows at Les Invalides (Paris) and the Sens Cathedral.

Relevant Publications:
Traité de la peinture sur verre (Paris, 1774).

Le Vieil, 1774: Éloge historique de Pierre le Vieil; Grove Art Online: K. C. Barley, "Stained Glass."

Lead white
Alternate names: White lead, Flake white, Cremnitz white, Kerms white, Cerussa.

Lead white, basic lead carbonate (2PC0Pb(OH)2) is one of the oldest manufactured pigments, the most important of the lead pigments and the most important white pigment in the eighteenth century.

The process to make lead white was unchanged for centuries: it required exposing strips of lead to vinegar in a warm, enclosed space. The combination of acetic acid (from the vinegar, carbonic acid and heat transformed the surface of the lead to lead carbonate. This was then scraped from the surface, washed, dried then further prepared for use: the unreacted lead was retuned to the preparation pot.

Gettens, Kühn and Chase, 1993: 67–81 (Artist's Pigments); Mayer, 1957: 101.

Web sites:
Museum of the History of Science, Oxford "Lead White" Web Link

Leithner, Josef (1807–1876)
Viennese porcelain painter to whom is credited the development of a cobalt-arsenate pigment (Leithner's blue).

Harley, 1982: 57.

Lemery, Nicolas (1645–1715)
French chemist and writer.

Lemery was the author of a much-reprinted (and variously re-written) treatise on chemistry.

Paris Academy of Sciences (1699)

Relevant Publications:
Cours de chymie contenant la maniere de faire les operations qui sont en usage dans la médecine, par une méthode facile (Paris, 1677).
Recueil de curiositez rares et nouvelles des plus admirables effets de la nature et de l'art (Paris, 1676).

DSB, 1970–80.

A name given to group of colorless or white-green liquids that are a stage in the chemical transformation of certain dyestuffs—vat dyes such as indigo and Tyrian purple, In general the color forms on exposure to oxygen, and forms in the fiber or on the substrate.

Kirk-Othmer, 1985.

Web sites:
IUPAC Compendium of Chemical Terminology, "Leuco" Web Link

Lewis, William (b. 1709, Richmond, Surrey; d. 1781, Kingston, Surrey)
English apothecary and writer.

William Lewis had a longstanding interest in practical chemistry and a strong belief in its value to the public. Evidence of this can be found throughout his life and his career. Lewis began to present public lectures on chemistry and the improvement of practical arts in the late 1730s.

Early Publications: included revision or abridgements of several existing work, including George Wilson's Complete Course of Chemistry, Compleat English Dispensatory, and The Chemical Works of Caspar Neumann.

Lewis served as a consultant to several manufacturing concerns. His own work included studies of platinum and gold, the creation of black-colored objects (mostly textiles), and the development of techniques to use chemistry as a means of identification. Some of these studies were published in Commercium philosophico-technicum, or, The Philosophical Commerce of Arts.

Royal Society of London
Society of Arts

Relevant Publications:
Commercium Philosophico-Technicum, or, The Philosophical Commerce of Arts (London, 1765).

Gibbs, 1952; Sivin, 1962; DNB Online:Fred G. Page, "William Lewis"; Gibbs, 1957.

Libavius, Andreas (b. ca. 1560, Halle; d. 1616, Coburg)
German chemist, alchemist and writer.

Libavius was a professor (history and poetry), a municipal physician, administrator, and chemist or alchemist. His chief publication in the sciences was a practical textbook, Alchemia.

Relevant Publications:
Alchemia (Frankfurt, 1597).

DSB, 1970–80: 8:309–12.

Web sites:
Rice University, Galileo Project, "Libavius" Web Link

Similar to: Litmus, Lacmus.
Names for lichens include archil, orchil, orcein, litmus, persio, parelle.

Lichens are composite parasite organisms that grow on rocks or tree trunks. The dominant portion is a fungus, but it can include other substances such as algae, from which it will feed.

Lichens can be used as a coloring material for textiles; they are best known as a source for certain red, blue, purple and violet colors. The coloring material tends to be pH-sensitive and has a long use as an acid-base indicator: the presence of acids will turn litmus (for example) red while the presence of alkalis will turn it blue.

Orchil is made from the lichen Rocella, native to the Mediterranean coast. The coloring material creates a dark purple color that can be manipulated to blues and reds.

Adrosko, 1971: 43–4; Schweppe, 1992: 517–35.

Web sites:
Lichen Biology and the Environment Web Link
Chris Cooksey's Website "Lichen Purple" Web Link
Encyclopedia Britannica (1911), "Litmus" Web Link
Getty Research Institute, Art and Architecture Thesaurus, "Orchil" Web Link

Lichtenberg, Georg Christoph (b. 1742, Oberramstadt, near Darmstat; d. 1799, Göttingen)
German physicist, writer and savant.

Lichtenberg studied and later taught—philosophy and mathematics—at the University of Göttingen. His scientific interests included the earth sciences (especially volcanology and meteorology), mathematics, and astronomy. He held the first chair of experimental physics at Göttingen, and was known for teaching the natural sciences through experiment.

Lichtenberg edited and published the work of Tobias Mayer, founder of the astronomical observatory at Göttingen.

Lichtenberg made two extended trips to England, the second as a guest of George III whom he had met on his earlier visit. While there, he became acquainted with many members of the British scientific community. His described those experiences for a German audience in several volumes that were an are known for their wit and freshness.

Royal Society of London
St. Petersburg Academy of Sciences

Relevant Publications:
Göttingisches Magazin der Literatur und Wissenschaft (editor, 1788–2).
Tobiae Mayeri ... Opera inedita (Göttingen, 1775).

Katrirsky, 1984; DSB, 1970–80: 8:320–22; DNB Online:Joachim Weihl, "Georg Christoph Lichtenberg."

Web sites:
Lichtenberg Gesellschaft Web Link

Alternate name: calcareous earth, quicklime.

Lime, calcium oxide (CaO) was a caustic substance used in textile bleaching and dyeing, in ceramic bodies, and in plaster (e.g., the ground layer for fresco painting).

Slaked lime, or calcium hydroxide, Ca(OH)2 is lime to which water has been added.

Mayer, 1957: 350–53.

Web sites:
Carmen Giunta, "Glossary of Archaic Chemical Terms," Classic Chemistry web site Web Link

Liver of sulfur
Alternate name: Hepar sulphuris, Sulfurated potash.

Liver of sulphur is any one of several reddish-brown (i.e., liver-colored) metal sulfides. In the eighteenth century, was prepared by fusing potash with sulfur.

Most often, it was a mixture of potassium and sulfur, made by fusing potassium carbonate and sulfur. Chemical composition could be K2S, K2S2, K2S3, K2S4, K2S5, or K2SO4.

Web sites:
Carmen Giunta, "Glossary of Archaic Chemical Terms," Classic Chemistry web site Web Link

Alternate names: India wood, Campeche, Blauholz (German), Bois de Campéche (French).

Native to Mexico, logwood (Haematoxylon Campechianum) is prepared by soaking the wood shavings and allowing them to ferment in the air: the coloring material was isolated in a boiling process similar to sugar extraction. The solution is brown-red but it turns a blue-violet when the dyebath is made alkaline, and yellow if acidic. Colors obtained range from violet-blue to violet to black, depending on the mordant.

Schweppe: 416–20; Brunello, 1973: 358–9.

Lomonosov, Mikhail Vasilievich (b. 1711, Mishaninskaya, Arkhangelsk province, Russia; d. 1765 St. Petersburg, Russia)
Russian chemist and scientist.

Lomonosov was the first Russian member of the St. Petersburg Academy of Sciences. Having shown remarkable capabilities, he was sent in 1736 to study with Christian Wolff at the University of Marburg. He then traveled to Freiberg to study (briefly) with Johann Henckel. Lomonosov returned to St. Petersburg in 1741 and remained in Russia for the rest of his life.

Lomonosov's main interests were poetry and the physical sciences. In 1748, he began to construct the first chemical laboratory in Russia. Among his commercial interests was a glass-mosaic factory, established in St. Petersburg in 1754, apparently based in part on his studies with Henckel. Other practical interests included construction of mills, scientific instruments and other machinery. He was engaged in several studies of color, of both colored glasses necessary to his manufacture and dyestuffs cultivated in Russia.

Theoretical investigations undertaken by Lomonosov included kinetic and chemical applications of corpuscular theories, optical phenomena, and geology.

St. Petersburg Academy of Sciences (1742)

DSB, 1970–80: 8:467–72; Leicester, 1969.

Loriot, Antoine Joseph (b. 1716, Bananns, bailage de Pontarlier; d. 1782, Paris)
French inventor.

Loriot, initially trained as a tinsmith, invented a wide range of mechanical devices for artisans and for industry. These included a lifting device that allowed a child to raise a large weight, a ribbon loom and a technique to fix pastel pictures. As a result of these experiences, the comte de Caylus hired him to develop a technique to tin mirrors.

Loriot later moved to Brittany, where he built a number of machines for aquatic and agricultural purposes. In 1761 he presented the Academy of sciences with a model of a machine to beat grains that could be operated by one person and do the work of 12 men. Several years later he demonstrated at the Trianon a mechanism that could raise and lower a fully laid table. He also invented a special fixative for the pastel medium, to prevent or slow deterioration of images.

Loriot worked on a mortar for hydraulic purposes that would be waterproof, and would harden to a stone-like permanence with time. His role as inventor was later disputed, as was his role in a device to raise water. In recognition of his inventions Loriot was given a pension of 1000 livres by Louis XV. A number of pamphlets describing his inventions survive.

Mercure: Feb. 1776; AN: 0/1/1915/50; O/1/1908/176; O/1/1919/147; NBG: "Loriot, Antoine Joseph."

Web sites:
Jean Pierre Cudennec, "Un Amateur des Arts, Antoine Joseph Loriot, Inventeur" Web Link

Lunar Society (Fl. 1775–1791)
A small (14 members) private society of men who lived in or near Birmingham. The group met monthly to discuss topics of interest to members, often relevant to their work.

Members included Erasmus Darwin, Samuel Galton, Joseph Priestley, Jonathan Stokes, James Watt, and Josiah Wedgwood.

Schofield, 1963.

Web sites:
Scholarly Societies Project, "Lunar Society of Birmingham" Web Link