Edward Schunck
Encyclopedia
Henry Edward Schunck was a British chemist who did much work with dyes.
, the son of Martin Schunck, a German merchant. He started studying chemistry in Manchester
with William Henry
. The young Schunck was sent to further his chemical studies to Berlin where he studied under Heinrich Rose
(1795–1864) who discovered niobium
, diligently analysed minerals and other inorganic substances and studied the chemistry of titanium, phosphorus, arsenic, antimony, sulfur, selenium and tellurium. Schunck also studied at Berlin under Heinrich Gustav Magnus (1802–1870) who published over 80 papers on many diverse topics in chemistry and physics. After studying in Berlin he received his PhD under Justus Liebig at the University of Gießen.
that in 1841 he published his first research paper, in Liebig's famous journal Annalen der Chemie. His topic concerned the effect of nitric acid on aloes. Schunck published his results in two papers in 1841 and 1848. The reaction between the aloe and nitric acid gives among other products, aloetic acid which on further reaction is converted into chrysammic acid. Glover (1855) describes the preparation: "Chrysammic acid ... is obtained by steeping 1 part of aloes in 8 of nitric acid, sp. gr. 1.37, and heating the mass in a porcelain capsule until the chief part of the action is over, then distilling off in a retort two-thirds of the nitric acid ; three or four parts of nitric acid are afresh introduced into the retort, and the whole kept for two or three days at a temperature near to boiling point. After disengagement of gas has ceased, water is added to the residue, which forms a precipitate - the chrysammic acid. The mother liquid contains oxalic and chrysolipic acids, which latter appears to be picric." Schunck analysed samples of chrysammic acid, now known to be 1,8–dihydroxy–2,4,5,7–tetranitroanthraquinone, and several of its metal salts, concluding that the formula of the acid was C15H3N4O12. This is very near to the currently accepted formula of C14H4N4O12 which was obtained by Mulder a few years later.
s was an important commercial product and came in a variety of forms, for example, orchil and cudbear. By the 1830s the researches of Pierre Jean Robiquet
(1780–1840), Friedrich Heeren
(1803–1885), Jean-Baptiste Dumas
and Robert John Kane (1809–1890) into the constituents of lichens had revealed three colour precursors: orcinol
, erythrin and pseudoerythrin, but their constitution was not precisely known. Liebig encouraged Schunck to reinvestigate the subject using dye-producing lichens that grow on the basalt rocks of the Vogelsberg
in Upper Hessia. In 1842, he discovered a new compound which he called lecanorin. His interpretation of the analyses of lecanorin (now called lecanoric acid) went astray because he used an incorrect formula for orcinol and because his lecanoric acid had partially hydrolysed to give orsellinic acid
leading to an incorrect result. The true story was unravelled by Stenhouse some years later. Later he discovered, in addition to lecanoric acid, another new compound, parellic acid from Lecanora parella.
Madder
was an important dye and imports into the UK were valued at £1.25 million per year in the 1860s. Schunck started his extensive investigations into the colouring materials in madder in 1846. The main colorant of madder was discovered by Robiquet and Colin in 1827 and called alizarin. Their analysis gave a formula C37H48O10. When purified by Schunck using sublimation and crystallisation, he obtained a result which suggested C14H8O4 , but taking into account the analyses of metal derivatives as well, he chose C14H10O4 as the best result. The modern formula is C14H8O4. He found that oxidation of alizarin with nitric acid gave alizaric acid (phthalic acid
) which on heating gave pyroalizaric acid (phthalic anhydride
). This led to the suggestion that alizarin was a derivative of naphthalene, a C10 hydrocarbon, although Schunck pointed out that this did not explain the reactions of alizarin. He was vindicated when Graebe and Liebermann (1868) distilled alizarin with zinc dust to give anthracene
, a C14 hydrocarbon, and subsequently (1869) synthesised alizarin
from anthraquinone
.
Schunck showed that alizarin was not the major colour precursor component of fresh madder root, but it was a yellow bitter water soluble component, which he called rubian. Rubian was obtained from the water extract of madder root by adding bone–charcoal and extracting the bone–charcoal with ethanol
. Rubian was an uncrystallisable gum, hydrolysable by acids or an enzyme contained in the madder root to give alizarin and a sugar. Rubian was actually a mixture of glycosides of di and trihydroxy anthraquinones of which a major component was ruberythric acid which is an alizarin 2–b–primeveroside. Many other “compounds” derived from the hydrolysis of rubian were described and enthusiastically named by Schunck: rubiretin, verantin, rubiacin, rubiadin, rubiapin, rubiafin and others, but some of these are most likely to be impure alizarin, and best forgotten. Some of Schunck's original samples were examined in 1975 by Wilfrid Farrar. Rubiadine was shown to be 1,3–dihydroxy–2–methyl anthraquinone, which Schunck assigned as the 4–methyl isomer. Rubiacine was identical to nordamnacanthal (1,3–dihydroxyanthraquinone–2–aldehyde) and rubianine was an unusual C–glucoside of unknown constitution.
, preferring the name indigo-blue to the alternative name, Indigotine. He grew woad
from "good French woad seed", extracted the dye precursor with cold ethanol and after further processing obtained a brown syrup which he called "indican
". "Indican" was quite unstable and resisted further purification. Later he also investigated Polygonum tinctorium and believed that it contained the same "indican". Only in the early years of the 20th century was it shown that Schunck's "indican" from woad was not the same as the indican from tropical indigo plants and Polygonum tinctorium, and it was renamed isatan, which was even later shown to be a mixture of isatan A, B and C.
The presence of indigo in urine has long been the subject of much curiosity and Schunck tried in 1857 to show that "indican" was the origin. Believing that the occurrence of indigo was more common than generally supposed at the time, he examined the urine of 40 individuals, all apparently healthy, with ages between 7 and 55 years, mostly of the working class. In all but one case the result was positive. The largest amount of indigo was obtained from a man above the age of 50, a publican by trade. In his own case, the amount "varied most capriciously from a tolerable quantity to a mere trace". He thought this variation might be due to different kinds of diet, but after many experiments, found only one which worked: "I took on the next night, before going to bed, a mixture of treacle and arrowroot boiled with water in as large a quantity as the stomach could bear, and the effect was that the urine of the following night gave a large quantity of indigo-blue". The indigo precursor in urine turns out not to be indican, although it was called medical indican at the time, but indoxyl sulfate or gluconurate.
and was honoured by the Society, and also by the Royal Society
and the Society of the Chemical Industry.
, which together with his library and collection of specimens were bequeathed to the Victoria University of Manchester
. He also donated £20,333 to the University for chemical research. The laboratory was removed from Kersal in 1904 and re-erected in Burlington Street next to other laboratories of the university. It is no longer used as a laboratory and is Grade II listed; the building is named after him. The room in which Schunck kept his library on the first floor is remarkably ornate. His books are now in the John Rylands University Library
and his specimens in the Museum of Science and Industry in Manchester
. Chaim Weizmann
spent a period working in this laboratory during his time at Manchester.
Early life and education
Henry Edward Schunck was born in ManchesterManchester
Manchester is a city and metropolitan borough in Greater Manchester, England. According to the Office for National Statistics, the 2010 mid-year population estimate for Manchester was 498,800. Manchester lies within one of the UK's largest metropolitan areas, the metropolitan county of Greater...
, the son of Martin Schunck, a German merchant. He started studying chemistry in Manchester
Manchester
Manchester is a city and metropolitan borough in Greater Manchester, England. According to the Office for National Statistics, the 2010 mid-year population estimate for Manchester was 498,800. Manchester lies within one of the UK's largest metropolitan areas, the metropolitan county of Greater...
with William Henry
William Henry (chemist)
William Henry was an English chemist.He was the son of Thomas Henry and was born in Manchester England. He developed what is known today as Henry's Law.-Life:...
. The young Schunck was sent to further his chemical studies to Berlin where he studied under Heinrich Rose
Heinrich Rose
Heinrich Rose was a German mineralogist and analytical chemist. He was the brother of the mineralogist Gustav Rose and a son of Valentin Rose....
(1795–1864) who discovered niobium
Niobium
Niobium or columbium , is a chemical element with the symbol Nb and atomic number 41. It's a soft, grey, ductile transition metal, which is often found in the pyrochlore mineral, the main commercial source for niobium, and columbite...
, diligently analysed minerals and other inorganic substances and studied the chemistry of titanium, phosphorus, arsenic, antimony, sulfur, selenium and tellurium. Schunck also studied at Berlin under Heinrich Gustav Magnus (1802–1870) who published over 80 papers on many diverse topics in chemistry and physics. After studying in Berlin he received his PhD under Justus Liebig at the University of Gießen.
Work
It was from GießenGießen
Gießen, also spelt Giessen is a town in the German federal state of Hesse, capital of both the district of Gießen and the administrative region of Gießen...
that in 1841 he published his first research paper, in Liebig's famous journal Annalen der Chemie. His topic concerned the effect of nitric acid on aloes. Schunck published his results in two papers in 1841 and 1848. The reaction between the aloe and nitric acid gives among other products, aloetic acid which on further reaction is converted into chrysammic acid. Glover (1855) describes the preparation: "Chrysammic acid ... is obtained by steeping 1 part of aloes in 8 of nitric acid, sp. gr. 1.37, and heating the mass in a porcelain capsule until the chief part of the action is over, then distilling off in a retort two-thirds of the nitric acid ; three or four parts of nitric acid are afresh introduced into the retort, and the whole kept for two or three days at a temperature near to boiling point. After disengagement of gas has ceased, water is added to the residue, which forms a precipitate - the chrysammic acid. The mother liquid contains oxalic and chrysolipic acids, which latter appears to be picric." Schunck analysed samples of chrysammic acid, now known to be 1,8–dihydroxy–2,4,5,7–tetranitroanthraquinone, and several of its metal salts, concluding that the formula of the acid was C15H3N4O12. This is very near to the currently accepted formula of C14H4N4O12 which was obtained by Mulder a few years later.
Dye-producing lichen
The purple from lichenLichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s was an important commercial product and came in a variety of forms, for example, orchil and cudbear. By the 1830s the researches of Pierre Jean Robiquet
Pierre Jean Robiquet
Pierre Jean Robiquet was a French chemist, who laid founding work in identifying amino acids, the fundamental bricks of proteins, through recognizing the first of them, asparagin, in 1806, in the take up of the industry of industrial dyes, with the identification of alizarin in 1826, and in the...
(1780–1840), Friedrich Heeren
Friedrich Heeren
Friedrich Heeren was a German chemist.-References:...
(1803–1885), Jean-Baptiste Dumas
Jean-Baptiste Dumas
Jean Baptiste André Dumas was a French chemist, best known for his works on organic analysis and synthesis, as well as the determination of atomic weights and molecular weights by measuring vapor densities...
and Robert John Kane (1809–1890) into the constituents of lichens had revealed three colour precursors: orcinol
Orcinol
Orcinol is a natural phenolic organic compound that occurs in many species of lichens including Rocella tinctoria and Lecanora. It can be formed by fusing extract of aloes with potash....
, erythrin and pseudoerythrin, but their constitution was not precisely known. Liebig encouraged Schunck to reinvestigate the subject using dye-producing lichens that grow on the basalt rocks of the Vogelsberg
Vogelsberg
Vogelsberg is a municipality in the Sömmerda district of Thuringia, Germany....
in Upper Hessia. In 1842, he discovered a new compound which he called lecanorin. His interpretation of the analyses of lecanorin (now called lecanoric acid) went astray because he used an incorrect formula for orcinol and because his lecanoric acid had partially hydrolysed to give orsellinic acid
Orsellinic acid
Orsellinic acid, more specifically o-orsellinic acid, is an organic acid. It is of importance in the biochemistry of lichens, from which it can be extracted. It can also be prepared by the oxidation of orcyl aldehyde....
leading to an incorrect result. The true story was unravelled by Stenhouse some years later. Later he discovered, in addition to lecanoric acid, another new compound, parellic acid from Lecanora parella.
In England; work on madder
In 1842 he came back to England and started a career in the chemical industry.Madder
Madder
Rubia is a genus of the madder family Rubiaceae, which contains about 60 species of perennial scrambling or climbing herbs and sub-shrubs native to the Old World, Africa, temperate Asia and America...
was an important dye and imports into the UK were valued at £1.25 million per year in the 1860s. Schunck started his extensive investigations into the colouring materials in madder in 1846. The main colorant of madder was discovered by Robiquet and Colin in 1827 and called alizarin. Their analysis gave a formula C37H48O10. When purified by Schunck using sublimation and crystallisation, he obtained a result which suggested C14H8O4 , but taking into account the analyses of metal derivatives as well, he chose C14H10O4 as the best result. The modern formula is C14H8O4. He found that oxidation of alizarin with nitric acid gave alizaric acid (phthalic acid
Phthalic acid
Phthalic acid is an aromatic dicarboxylic acid, with formula C6H42. It is an isomer of isophthalic acid and terephthalic acid. Although phthalic acid is of modest commercial importance, the closely related derivative phthalic anhydride is a commodity chemical produced on a large...
) which on heating gave pyroalizaric acid (phthalic anhydride
Phthalic anhydride
Phthalic anhydride is the organic compound with the formula C6H42O. It is the anhydride of phthalic acid. This colourless solid is an important industrial chemical, especially for the large-scale production of plasticizers for plastics. In 2002, approximately 4.6 billion kilograms were...
). This led to the suggestion that alizarin was a derivative of naphthalene, a C10 hydrocarbon, although Schunck pointed out that this did not explain the reactions of alizarin. He was vindicated when Graebe and Liebermann (1868) distilled alizarin with zinc dust to give anthracene
Anthracene
Anthracene is a solid polycyclic aromatic hydrocarbon consisting of three fused benzene rings. It is a component of coal-tar. Anthracene is used in the production of the red dye alizarin and other dyes...
, a C14 hydrocarbon, and subsequently (1869) synthesised alizarin
Alizarin
Alizarin or 1,2-dihydroxyanthraquinone is an organic compound with formula that has been used throughout history as a prominent dye, originally derived from the roots of plants of the madder genus.Alizarin was used as a red dye for the English parliamentary "new model" army...
from anthraquinone
Anthraquinone
Anthraquinone, also called anthracenedione or dioxoanthracene is an aromatic organic compound with formula . Several isomers are possible, each of which can be viewed as a quinone derivative...
.
Schunck showed that alizarin was not the major colour precursor component of fresh madder root, but it was a yellow bitter water soluble component, which he called rubian. Rubian was obtained from the water extract of madder root by adding bone–charcoal and extracting the bone–charcoal with ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
. Rubian was an uncrystallisable gum, hydrolysable by acids or an enzyme contained in the madder root to give alizarin and a sugar. Rubian was actually a mixture of glycosides of di and trihydroxy anthraquinones of which a major component was ruberythric acid which is an alizarin 2–b–primeveroside. Many other “compounds” derived from the hydrolysis of rubian were described and enthusiastically named by Schunck: rubiretin, verantin, rubiacin, rubiadin, rubiapin, rubiafin and others, but some of these are most likely to be impure alizarin, and best forgotten. Some of Schunck's original samples were examined in 1975 by Wilfrid Farrar. Rubiadine was shown to be 1,3–dihydroxy–2–methyl anthraquinone, which Schunck assigned as the 4–methyl isomer. Rubiacine was identical to nordamnacanthal (1,3–dihydroxyanthraquinone–2–aldehyde) and rubianine was an unusual C–glucoside of unknown constitution.
Work on indigo
In 1855, Schunck turned his attention to the subject of indigoIndigo
Indigo is a color named after the purple dye derived from the plant Indigofera tinctoria and related species. The color is placed on the electromagnetic spectrum between about 420 and 450 nm in wavelength, placing it between blue and violet...
, preferring the name indigo-blue to the alternative name, Indigotine. He grew woad
Woad
Isatis tinctoria, with Woad as the common name, is a flowering plant in the family Brassicaceae. It is commonly called dyer's woad, and sometimes incorrectly listed as Isatis indigotica . It is occasionally known as Asp of Jerusalem...
from "good French woad seed", extracted the dye precursor with cold ethanol and after further processing obtained a brown syrup which he called "indican
Indican
Indican is a colourless organic compound, soluble in water, naturally occurring in Indigofera plants. It is a precursor of indigo dye.-Chemical reactions:Common and significant reactions involving indican are as follows:...
". "Indican" was quite unstable and resisted further purification. Later he also investigated Polygonum tinctorium and believed that it contained the same "indican". Only in the early years of the 20th century was it shown that Schunck's "indican" from woad was not the same as the indican from tropical indigo plants and Polygonum tinctorium, and it was renamed isatan, which was even later shown to be a mixture of isatan A, B and C.
The presence of indigo in urine has long been the subject of much curiosity and Schunck tried in 1857 to show that "indican" was the origin. Believing that the occurrence of indigo was more common than generally supposed at the time, he examined the urine of 40 individuals, all apparently healthy, with ages between 7 and 55 years, mostly of the working class. In all but one case the result was positive. The largest amount of indigo was obtained from a man above the age of 50, a publican by trade. In his own case, the amount "varied most capriciously from a tolerable quantity to a mere trace". He thought this variation might be due to different kinds of diet, but after many experiments, found only one which worked: "I took on the next night, before going to bed, a mixture of treacle and arrowroot boiled with water in as large a quantity as the stomach could bear, and the effect was that the urine of the following night gave a large quantity of indigo-blue". The indigo precursor in urine turns out not to be indican, although it was called medical indican at the time, but indoxyl sulfate or gluconurate.
Personal life
His married Judith H. Brooke in 1851 and was survived by his four children. Before retiring early he was in business as a calico printer. He was for some years president of the Manchester Literary and Philosophical SocietyManchester Literary and Philosophical Society
The Manchester Literary and Philosophical Society, popularly known as the Lit & Phil, is a learned society in Manchester, England.Established in 1781 as the Literary and Philosophical Society of Manchester, by Thomas Percival, Thomas Barnes and Thomas Henry, other prominent members have included...
and was honoured by the Society, and also by the Royal Society
Royal Society
The Royal Society of London for Improving Natural Knowledge, known simply as the Royal Society, is a learned society for science, and is possibly the oldest such society in existence. Founded in November 1660, it was granted a Royal Charter by King Charles II as the "Royal Society of London"...
and the Society of the Chemical Industry.
Legacy
Schunck built a private laboratory in the grounds of his home, "The Oaklands", in KersalKersal
Kersal is an inner city area of Salford, in Greater Manchester, England. The centre of Kersal is northwest of Manchester city centre, and north-northwest of Salford's conventional centre at Greengate....
, which together with his library and collection of specimens were bequeathed to the Victoria University of Manchester
Victoria University of Manchester
The Victoria University of Manchester was a university in Manchester, England. On 1 October 2004 it merged with the University of Manchester Institute of Science and Technology to form a new entity, "The University of Manchester".-1851 - 1951:The University was founded in 1851 as Owens College,...
. He also donated £20,333 to the University for chemical research. The laboratory was removed from Kersal in 1904 and re-erected in Burlington Street next to other laboratories of the university. It is no longer used as a laboratory and is Grade II listed; the building is named after him. The room in which Schunck kept his library on the first floor is remarkably ornate. His books are now in the John Rylands University Library
John Rylands University Library
The John Rylands University Library is the University of Manchester's library and information service. It was formed in July 1972 from the merger of the library of the Victoria University of Manchester with the John Rylands Library...
and his specimens in the Museum of Science and Industry in Manchester
Museum of Science and Industry in Manchester
The Museum of Science and Industry in Manchester, England, is a large museum devoted to the development of science, technology, and industry with emphasis on the city's achievements in these fields...
. Chaim Weizmann
Chaim Weizmann
Chaim Azriel Weizmann, , was a Zionist leader, President of the Zionist Organization, and the first President of the State of Israel. He was elected on 1 February 1949, and served until his death in 1952....
spent a period working in this laboratory during his time at Manchester.