Hall, Stephen (Fl. 1760–80)
Proprietor of the Falcon Glassworks, Southwark, London.

George Berg, Experiment Book; Buckley, 1915.

Hancock, Robert (b. 1731, Badsey, Hereford and Worcestershire; d. 1817, Brislington, Avon, England)
English engraver and ceramics manufacturer.

Hancock was trained as an engraver and in 1756 went to work at the Worcester Porcelain Company, a firm founded in 1751 which made soft-paste porcelain wares. Hancock became a partner in this concern in 1772. Tradition, and evidence of some enamels decorated with transfer-prints, also link Hancock's name with the Battersea Enamel Works (c. 1747–56), a manufacture known for snuff boxes, wine labels and other small objects, made of enameled copper decorated with transfer-printed engravings.

Hancock left the Worcester manufacture in 1774, worked briefly at another pottery and then became a freelance artist-engraver. He engraved plates for books and plates for mezzotint copies of painting; his own painting were exhibited at the Royal Academy of Arts in the early nineteenth century.

Royal Academy of Art

Cook, 1947; Grove Art Online: Norman Stretton "Robert Hancock."

Harris, Moses (1731?–1785?)
English entomologist and engraver.

Harris, the author of The Aurelian published most about moths and butterflies, his writing is said to demonstrate close observation; the Natural System of Colours was the only non-entomological book he produced.

Originally published in 1766, Harris's Natural System of Colours is better-known through its reprints, especially one edited by Thomas Martyn (London, 1811) and a facsimile reproduction, in the 1960s, edited by the colorist Faber Birren.

Werner Spillmann has recently suggested that the publication date was actually 1771.

The Aurelian Society

Relevant Publications:
The Natural System of Colours, Wherein is Displayed the Regular and Beautiful Order and Arrangement, Arising from the Three Primitives. . . (London, [1766]).

Birren, 1963; Schmid, F; DSB, 1970–80:(1968) v 9 p 20; Spillmann, 2004.

Hassenfratz, Jean Henri (b. 1755, Paris; d. 1827, Paris)
French chemist and savant.

Hassenfratz was a member of the Institute de France (Academy of Sciences) and a professor at the École Polytechnique. He played an active if subaltern role in the Revolution.

Hassenfratz was a master carpenter and a surveyor before he was named a mining student; he was sent to central Europe to study that subject. In 1785 he was named a deputy inspector of mines. Hassenfratz worked in Lavoisier's laboratory and taught physics and mineralogy at the École des Mines.

Relevant Publications:
Méthode de nomenclature chimique (assisted Lavoisier, Berthollet, Fourcroy and Guyton de Morveau) (Paris, 1787).

DSB, 1970–80: 6:164–5; Michaud, 1966: 18: 50–1.

Web sites:
Euromin, "Jean Henri Hassenfratz" Web Link

Haussmann, Jean-Michel (1749–1824)
French chemist and industrialist.

Haussmann, the son of an apothecary in Colmar, was sent to study for that occupation in Geneva and in Paris. Finding that he had an interest in chemistry and physics, he spent much of his time studying and writing —and applying his knowledge to practical uses, especially textiles. In 1775 he opened an indiennes manufacture in Rouen, obtaining a royal privilege for it in 1776. He later opened a similar factory in Logelbach (near Colmar) for which he found he had to reformulate his recipes. Haussmann is credited as the first among French manufacturers to use English blue in textile printing he also was one of the first to use Prussian blue on cotton and linen.

Haussmann turned to concentrate on research after the revolution, maintaining relations with Lavoisier, Fourcroy, Chaptal, Berthollet, etc.

Relevant Publications:
Many contributions to Crell's Journals 1778–1791, Annals de Chimie, and other scientific periodicals.

Haussmann, 1792; Michaud, 1966: 17:735; Nieto-Galan, 2001:53.

Hayman, Francis (b. 1708, Exeter; d. 1776, London)
English painter.

Hayman was apprenticed to a decorative painter in London at the age of 10, and the early work for which he is known is scene painting and decoration in theaters in London. Not much of this work has survived except by its reputation and occasional engravings. Portraits and conversation pieces (group portraits in a casual setting) began to occupy his time by the late 1730s. His best-known theatrical commission, the supper boxes at the Vauxhall Gardens theater, was taken in the 1740s, however.

In addition to portraits, Hayman was also engaged in history paintings such as The Finding of the Infant Moses; he was an advocate for the importance of this genre of painting to the development of a distinctly English painting style. This attitude was typical of those who supported the founding of an English academy of painting, as Hayman did.

Hayman also worked as an illustrator, designing and executing engravings for book publishers, including editions of Congreve and Shakespeare.

St. Martin's Lane Academy (from ca. 1745)
Committee for Founding a Public Academy (1755, chairman)
Society of Artists of Great Britain (Chairman, 1765–8)
Royal Academy (founding member, 1768)

Grove Art Online: Shearer West, "Francis Hayman"; Allen, 1987.

Hecquet d'Orval (Fl. 1780)
Owner of a textile manufacture in Abbeville, specializing in moquettes—coarse wool or linen velvet used mainly for upholstery.

Hecquet d'Orval, with Ribaucour, received half of a 1200 livre prize from the Paris Academy of Sciences for their essay on indigo.

Relevant Publications:
"Mémoire sur l'Indigo, Tel Qu'il Est dans le Commerce, pour l'Usage de la Teinture," Mémoires de mathématique et de physique, présentés à l'Académie royale des Sciences, par divers sçavans, & lûs dans ses assemblées 9 (1780): 81–120.

Sav. Étr., 1780: Title page.

Hellot, Jean (b. 1685, Paris; d. 1766, Paris)
French academician, chemist and writer.

Hellot's inherited fortune was lost in John Law's scheme, leading him to become editor of the Gazette de France from 1718 until 1732, when he decided on a career in the sciences, and specifically in chemistry. (He was 47 years old.)

Hellot studied chemistry under Étienne François Geoffroy and was elected to the Paris Academy of Sciences in 1735. Five years later, he was named inspector general of dyeing and later became a technical advisor at the Vincennes manufacture, where he conducted systematic investigations of clays, glazes and enamels.

Hellot's research, presented to the Paris Academy, was wide ranging, and always marked by careful and precise analytical techniques. Much of his work was directed to improve manufactures.

Paris Academy of Sciences
Royal Society of London
Inspector general of dyeing (1740)
Technical advisor to the Vincennes/Sèvres manufacture (1751)

Relevant Publications:
L'art de teinture des laines et des étoffes de laine en grand et petit teint (Paris, 1750).
Numerous Publications: in the Mémoires de l'Académie royale des Sciences.

DSB, 1970–80: 6:236–7; Todericu, 1976; Todericu, 1977; AdS: Dossier biographique "Jean Hellot."

Web sites:
AdS "In Memoriam" Web Link

Henckel, Johann (b. 1678, Merseburg, Germany; d. 1744, Freiberg, Saxony)
German mineralogist, metallurgist and experimenter.

Henckel trained in medicine, and became the town physician and mine physician in Freiberg (Saxony) in 1721. This position gave him the leisure to explore chemistry and to publish his discoveries. Among his interests were the similarities between plants and minerals and the nature of pyrites.

Henckel was appointed counsellor of mines for Saxony in 1732. Having lived for some years in Dresden, he returned to Freiberg where he established a laboratory, taught metallurgical chemistry an continued his research. Among his students were Mikhail Lomonosov and Andreas Marggraf. Henckel's work, strongly influenced by his own teacher, Georg Stahl, did much to disseminate the Stahlian approach to chemistry and matter.

Relevant Publications:
Flora saturnians (Leipzig, 1722).

DSB, 1970–80: 6:259–10.

Henry, Thomas (1734–1816)
English apothecary and savant.

Henry was the leading chemist in Manchester from the 1770s until the arrival of John Dalton in the 1790s and he was an active member of the scientific community in that city until his death. The owner of an apothecary practice in Manchester, he was deeply involved in the early years of the Manchester Literary and Philosophical Society.

Manchester Literary and Philosophical Society

Relevant Publications:
"On the Advantages of Literature and Philosophy in General, and Especially on the Consistency of Literary and Philosophical, with Commercial Pursuits," Memoirs of the Literary and Philosophical Society of Manchester 1 (1785): 7–29.
"Considerations Relative to the Nature of Wool, Silk and Cotton, as Objects of The Art of Dying . . . ," Memoirs of the Literary and Philosophical Society of Manchester 3 (1790) 343–408.

Kargon, 1977: 7–11; Farrar, Brock and Leslie, 1977.

Hermbstädt, Sigismund Friedrich (b. 1760, Erfurt, Germany; d. 1833, Berlin)
German chemist, apothecary and writer.

Hermbstädt began a study of medicine but his interests led him to concentrate on chemistry. He attended Johann Christian Wiegleb's school in Langensalza and obtained a doctorate in chemistry. Hermbstaedt was friendly with Martin Klaproth, among other members of the Berlin medical-chemical community; his connection to Klaproth led to and a position managing the Schwan-Apotheke in Berlin. In 1788, Hermbstädt established a boarding school for chemistry students in Berlin and he founded the Magazin für die Technologie, and was an advisor to the Wegley chemical factories. He served as commissioner or administrator of several chemistry or technology related bodies, including chief apothecary to the Prussian army, professor of chemistry and chemical technology.

Hermbstädt was a prolific writer on chemical subjects, including an annotated translation of Lavoisier's Traité élémentaire de chimie.

Berlin Academy of Sciences
Society for the Encouragement of Industry

DSB, 1970–80: 5:205–7; Hufbauer, 1982: 210–2; Harnack, 1900.

Highmore, Joseph (b. 1692, Canterbury; d. 1782, London)
English painter and writer.

Highmore abandoned a law career to become a painter, studying first at Godfrey Kneller's school, and then at the St. Martin's Lane Academy. He studied Brook Taylor's system of perspective, and attended anatomy lectures as well, contributing drawings to William Cheselden's Anatomy of the Human Body.

Highmore specialized in portraiture; a painting donated to Thomas Coram's Hospital (Hagar and Ishmael) is uncharacteristic in its historical subject.

Highmore retired from painting in 1762 and took to writing on art, aesthetics and perspective.

Society of Artists of Great Britain

Relevant Publications:
The Practice of Perspective, on the Principals of Dr Brook Taylor (London, 1763).

Grove Art Online: Shearer West "Joseph Highmore."

Hill, John (b. 1715, Peterborough, England; d. 1775, London)
English botanist and author.

Hill's interest in plants was s source of income, supplementing his earnings as an apothecary: he created herbal remedies and he collected botanical specimens for others. He was one of the first authors to apply a Linnaean system English flora. Hill was an editor of the British Magazine and a contributor to Chambers Cyclopaedia.

An ingenius man but lacking veracity (according to Dr. Johnson), Hill was denied admission to the Royal Society and published an attack on that group.

DSB, 1970–80: 6:400–1; DNB.

Hogarth, William (b. 1697, London; d. 1764, London)
English artist and engraver.

Hogarth's formal training was as an engraver, and he appears to have been a self-taught painter. He is best remembered for several series of satirical engravings (e.g., The South Sea Scheme, 1721; A Harlot's Progress, 1732; Marriage à la Mode, 1743). The engravings were taken—by Hogarth himself—from paintings made by Hogarth. This allowed him control over the sale of reproductions of images he created, a control established further by his involvement in passage of the Engravers Copyright Act (1735) which prohibited unauthorized copying of engravings for fourteen years after the initial publication. Hogarth was instrumental in the creation of an English school of painting, through his efforts to improve the status of painters.

St. Martin's Lane Academy
Sergeant-Painter to the King, 1757 (a salaried position supervising decorative works)
Society of Artists of Great Britain
Society of Arts

Relevant Publications:
The Analysis of Beauty (London, 1753).

Grove Art Online: Sheila O'Connell, "William Hogarth."

Holker, John (b. 1719, Stretford (Manchester); d. 1786, Rouen)
English manufacturer, in employ of the French (Rouen) textile and manufacturing industry.

Holker had been a partner in a calendering business in Manchester; he fought with Charles Edward Stewart and at Stewart's defeat moved to France. He came to the attention of several French administrators who asked him to establish a series of manufactures in Rouen. These manufactures would raise the quality of Rouen cottons to the standard set by England. He returned to England, gathered workers and machine models and returned to run two successful enterprises in Rouen.

Holker became inspector-general of foreign manufactures in 1756. From about 1768 he operated, with his son, a chemical factory to make vitriol.

Harris, 1998; Remond, 1946.

Homassel, Nicolas Charles (Fl. 1770s–1806)
French dyer, affiliated with the Gobelins tapestry manufacture.

Nothing definitive is known about Homassel's early training in dyeing or dye chemistry, nor about his life or work after he left the manufacture.

Homassel came to the Gobelins manufacture in 1778, and remained there until 1787, advancing from student to head of dyeing. He worked under Quemiset, and was taught chemistry by Pierre-Joseph Macquer, Mittoire (Pierre-François Mitouard?), and Jean-Baptiste Bucquet.
There is some highly circumstantial evidence of an eighteenth century connection to the Hecquet family, textile manufacturers in Abbeville.

The first edition (1798) of Homassel's treatise is dedicated to Jean-François Sacombe, a poet and obstetrician: Sacombe later claimed to have edited the original publication. Details of this connection are unknown. The second edition (1807) was edited by Edmé Bouillon-Lagrange.

Homassel, 1798: i-iv; Certificat de vertu, 6 February 1785, AN/0/1/2051.

Hoofnail, John (Fl. 1730s, England)
English writer and experimenter.

Relevant Publications:
New Practical Improvements, and Observations on Some of the Experiments and Considerations Touching Colours (London, 1738).

Hoofnail, 1738.

Hooke, Robert (b. 1635, Isle of Wight; d. 1702, London)
English natural philosopher and experimenter.

At Oxford in the 1650s, Hooke was part of a circle that would become the core of the Royal Society of London. He worked as an assistant to John Willis and, later, to Robert Boyle. He experimented with air pumps and chronometers. Hooke had a wide range of interests and followed many of them through research; this led to his proposal as curator of experiment for the newly formed Royal Society. He lectured in mechanics and geometry and, after the great fire of London, worked with Christopher Wren to survey and rebuild the city. An interest in microscopes led him to publish one of the first books on microscopical observations.

Hooke's interest in light led to confrontations with Newton, based on his critique of Newton's work. (Hooke maintained that colors were due to the modification of light.).

Royal Society of London

Relevant Publications:
Micrographica (London, 1665).

DSB, 1970–80: 6:481–8.

The dominant attribute of color, e.g., red, yellow, green, blue. Hue is determined by the dominant wavelength of the light thus it is related to colors in the spectrum.

Nassau, 1983: 9; Kuehni, 2005: 41–2.

Web sites: Web Link

Huile d'aspic
Alternate name: Lavender oil.

A slow-drying oil, used as an additive to oil paints and varnishes.

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