John Stevens Henslow
Encyclopedia
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
clergyman, botanist and geologist
Geologist
A geologist is a scientist who studies the solid and liquid matter that constitutes the Earth as well as the processes and history that has shaped it. Geologists usually engage in studying geology. Geologists, studying more of an applied science than a theoretical one, must approach Geology using...
. He is best remembered as friend and mentor to his pupil Charles Darwin
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
.
Early life
Henslow was born at Rochester, the son of a solicitor John Prentis Henslow, who was the son of Sir John HenslowJohn Henslow
Sir John Henslow was Surveyor to the Navy a post he held jointly or solely from 1784 to 1806.-Career:He was 7th child of John Henslow a master carpenter in the dockyard at Woolwich...
.
Henslow was educated at St. John's College, Cambridge where he graduated as 16th wrangler in 1818, the year in which Adam Sedgwick
Adam Sedgwick
Adam Sedgwick was one of the founders of modern geology. He proposed the Devonian period of the geological timescale...
became Woodwardian Professor of Geology
Woodwardian Professor of Geology
The Woodwardian Professor of Geology is a professorship held in the Department of Earth Sciences at the University of Cambridge. It was founded by John Woodward in 1728...
.
Early career
Henslow graduated in 1818. He already had a passion for natural historyNatural history
Natural history is the scientific research of plants or animals, leaning more towards observational rather than experimental methods of study, and encompasses more research published in magazines than in academic journals. Grouped among the natural sciences, natural history is the systematic study...
from his childhood, which largely influenced his career, and he accompanied Sedgwick
Adam Sedgwick
Adam Sedgwick was one of the founders of modern geology. He proposed the Devonian period of the geological timescale...
in 1819 on a tour in the Isle of Wight
Isle of Wight
The Isle of Wight is a county and the largest island of England, located in the English Channel, on average about 2–4 miles off the south coast of the county of Hampshire, separated from the mainland by a strait called the Solent...
where he learned his first lessons in geology. He also studied chemistry
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
under Professor James Cumming
James Cumming
Rev. Prof. James Cumming was the ninth Professor of Chemistry in Cambridge from 1815 to 1860. Cumming is remembered for his research-led teaching and his lectures during which he would literally shock the audience with a galvanic apparatus...
and mineralogy
Mineralogy
Mineralogy is the study of chemistry, crystal structure, and physical properties of minerals. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization.-History:Early writing...
under Edward Daniel Clarke
Edward Daniel Clarke
Edward Daniel Clarke was an English naturalist, mineralogist and traveller.-Life:Edward Daniel Clarke was born at Willingdon, Sussex, and educated first at Tonbridge....
. In the autumn of 1819 he made valuable observations on the geology of the Isle of Man
Isle of Man
The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...
(Trans. Geol. Soc., 1821) and in 1820 and 1821 he investigated the geology of parts of Anglesey
Anglesey
Anglesey , also known by its Welsh name Ynys Môn , is an island and, as Isle of Anglesey, a county off the north west coast of Wales...
, the results being printed in the first volume of the Transactions of the Cambridge Philosophical Society
Cambridge Philosophical Society
The Cambridge Philosophical Society is a scientific society at University of Cambridge. It was founded in 1819. The name derives from the medieval use of the word philosophy to denote any research undertaken outside the fields of theology and medicine...
(1822), the foundation of which society was originated in November 1819 by a group at Cambridge with Professors Farish
William Farish (professor)
William Farish was a British scientist who was a professor of Chemistry and Natural Philosophy at the University of Cambridge, known for the development of the method of isometric projection and development of the first written university examination.- Biography :Farish's father was the Reverend...
, Lee, and Sedgwick and Henslow (at that time not yet a professor). The idea and initial impetus for the Society originated from Sedgwick and Henslow.
Meanwhile, Henslow had studied mineralogy with considerable zeal, so that on the death of Clarke he was in 1822 appointed Professor of Mineralogy in the University of Cambridge. Two years later he took holy orders. Botany, however, had claimed much of his attention, and to this science he became more and more attached, so that he gladly resigned the chair of Mineralogy in 1827, two years after becoming Professor of Botany. As a teacher both in the classroom and in the field he was eminently successful. He was a correspondent of John James Audubon
John James Audubon
John James Audubon was a French-American ornithologist, naturalist, and painter. He was notable for his expansive studies to document all types of American birds and for his detailed illustrations that depicted the birds in their natural habitats...
who in 1829 named Henslow's Sparrow
Henslow's Sparrow
Henslow's Sparrow, Ammodramus henslowii, is a small American sparrow.Adults have streaked brown upperparts with a light brown breast with streaks, a white belly and a white throat...
after him.
From 1821 Henslow had begun organising a herbarium
Herbarium
In botany, a herbarium – sometimes known by the Anglicized term herbar – is a collection of preserved plant specimens. These specimens may be whole plants or plant parts: these will usually be in a dried form, mounted on a sheet, but depending upon the material may also be kept in...
of British flora, supplementing his own collecting with a network which expanded over time to include his friends and family, and the botanists William Jackson Hooker
William Jackson Hooker
Sir William Jackson Hooker, FRS was an English systematic botanist and organiser. He held the post of Regius Professor of Botany at Glasgow University, and was the first Director of the Royal Botanic Gardens, Kew. He enjoyed the friendship and support of Sir Joseph Banks for his exploring,...
and John Hutton Balfour
John Hutton Balfour
John Hutton Balfour was a Scottish botanist. Balfour became a Professor of Botany, first at the University of Glasgow in 1841, moving to Edinburgh University and also becoming Regius Keeper of the Royal Botanic Garden Edinburgh and Her Majesty's Botanist in Scotland in 1845...
, as well as about 30 of his students. As a mineralogist he had used Haüy's
René Just Haüy
René Just Haüy – 3 June 1822 in Paris) was a French mineralogist, commonly styled the Abbé Haüy after he was made an honorary canon of Notre Dame. He is often referred to as the "Father of Modern Crystallography." -Biography:...
laws of crystallography to analyse complex crystals as transformations of "the primitive form of the species" of crystal, and when he moved to botany in 1825 he sought similarly precise laws to group plant varieties into species, often including as varieties plants that respected taxonomists
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
had ranked as separate species. He followed the understanding of the time that species were fixed as created but could vary within limits, and hoped to analyse these limits of variation. By a method he called "collation", Henslow prepared sheets with several plant specimens, each labelled with the collector, date and place of collection, comparing the specimens to show the variation within the species. His A Catalogue of British Plants was first published in October 1829, and became a set book for his lecture course. Earlier that year, Charles Darwin
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
joined the course and along with other students helped to collect plants of Cambridgeshire. In 1830 Henslow experimented on varying the conditions of garden grown wild plants to produce various forms of the plant. In 1835 Henslow published Principles of Descriptive and Physiological Botany as a textbook based on this lecture course.
In the summer of 1831 Henslow was offered a place as naturalist to sail aboard the survey ship HMS Beagle
HMS Beagle
HMS Beagle was a Cherokee-class 10-gun brig-sloop of the Royal Navy. She was launched on 11 May 1820 from the Woolwich Dockyard on the River Thames, at a cost of £7,803. In July of that year she took part in a fleet review celebrating the coronation of King George IV of the United Kingdom in which...
on a two-year voyage
Second voyage of HMS Beagle
The second voyage of HMS Beagle, from 27 December 1831 to 2 October 1836, was the second survey expedition of HMS Beagle, under captain Robert FitzRoy who had taken over command of the ship on its first voyage after her previous captain committed suicide...
to survey South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, but his wife dissuaded him from accepting. Seeing a perfect opportunity for his protégé, Henslow wrote to the ship’s captain Robert Fitzroy
Robert FitzRoy
Vice-Admiral Robert FitzRoy RN achieved lasting fame as the captain of HMS Beagle during Charles Darwin's famous voyage, and as a pioneering meteorologist who made accurate weather forecasting a reality...
telling him that Darwin was the ideal man to join the expedition team. During the voyage, Darwin corresponded with Henslow, and collected plants with him in mind. In particular, when first arriving at the Galápagos Islands
Galápagos Islands
The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
Darwin noted "I certainly recognize S America in Ornithology, would a botanist?", and went on to collect plant specimens carefully labelled by island and date. He also labelled the mockingbird
Mockingbird
Mockingbirds are a group of New World passerine birds from the Mimidae family. They are best known for the habit of some species mimicking the songs of other birds and the sounds of insects and amphibians, often loudly and in rapid succession. There are about 17 species in three genera...
s he caught, and initially thought these were varieties but while arranging these bird specimens on the last lap of the voyage he began wondering if they could be species, a possibility which would "undermine the stability of Species". Henslow's teaching continued to influence Darwin's work on evolution.
Besides Darwin, other famous students of Henslow included Berkeley
Miles Joseph Berkeley
Miles Joseph Berkeley was an English cryptogamist and clergyman, and one of the founders of the science of plant pathology....
, Babington, Lowe
Richard Thomas Lowe
Richard Thomas Lowe was a British botanist, ichthyologist, malacologist, and clergyman. In 1825 he graduated from Christ's College, Cambridge and in the same year took holy orders. He became a clergyman in the Madeira Islands in 1832, where he was a part-time naturalist, extensively studying the...
and Miller
William Hallowes Miller
William Hallowes Miller FRS , British mineralogist and crystallographer.- Life and work :Miller was born in 1801 at Velindre near Llandovery, Carmarthenshire. He was educated at St John's College, Cambridge, where he graduated in 1826 as fifth wrangler. He became a Fellow there in 1829...
. Henslow founded the Cambridge University Botanic Garden
Cambridge University Botanic Garden
The Cambridge University Botanic Garden is a botanical garden located in Cambridge, England. It lies between Trumpington Road to the west and Hills Road to the east, close to Cambridge railway station. The garden covers an area of 16 hectares...
in 1831. During his time at Cambridge he extended the Botanic Garden and remodelled the 40-acre site between Bateman Street and Brooklands Avenue, making it world-renowned.
A country clergyman
In 1833 Henslow was appointed vicar of CholseyCholsey
Cholsey is a village and civil parish south of Wallingford, in South Oxfordshire. In 1974 it was transferred from Berkshire to the county of Oxfordshire, and from Wallingford Rural District to the district of South Oxfordshire....
-cum-Moulsford
Moulsford
Moulsford is a village and civil parish in South Oxfordshire. In 1974 it was transferred from Berkshire to the county of Oxfordshire, and from Wallingford Rural District to the district of South Oxfordshire....
in Berkshire
Berkshire
Berkshire is a historic county in the South of England. It is also often referred to as the Royal County of Berkshire because of the presence of the royal residence of Windsor Castle in the county; this usage, which dates to the 19th century at least, was recognised by the Queen in 1957, and...
(now Oxfordshire
Oxfordshire
Oxfordshire is a county in the South East region of England, bordering on Warwickshire and Northamptonshire , Buckinghamshire , Berkshire , Wiltshire and Gloucestershire ....
). He continued to live in Cambridge, only visiting the parish during vacations; no doubt he appointed a curate
Curate
A curate is a person who is invested with the care or cure of souls of a parish. In this sense "curate" correctly means a parish priest but in English-speaking countries a curate is an assistant to the parish priest...
to conduct services and parish business during term-time.
However, his appointment in 1837 to the remunerative Crown living at Hitcham, Suffolk
Hitcham, Suffolk
Hitcham is a village and civil parish in Suffolk, England. Located on the B1115 road, between Hadleigh and Stowmarket, it is part of Babergh district. The parish contains the hamlets of Bird Street, Cook's Green and Cross Green....
marked a turning-point in his life. This time, in 1839, he moved to the parish, and as Rector of Hitcham he lived at the Rectory. He worked there, endearing himself to all who knew him, until the end of his life. His energies were devoted to the improvement of his parishioners, but his influence was felt far and wide. Botany at Cambridge suffered, attendance at lectures fell, and we have records of complaints made within the university. Henslow did not resign his Chair, and continued to give lectures, set and mark exams, and take part in university affairs. Nevertheless, his influence there was naturally much reduced.
Henslow's work in Hitcham, over and above the normal duties of a Rector, can be summarised as follows:
- 1. The Parish School and other charities. Hitcham was a poor parish, and most people would have been illiterate. Education had to be paid for, and so Henslow both raised funds and donated his own money to support a school. The school was founded in 1841, and Henslow himself gave a series of volunteer classes on Monday afternoons for some of the older children. Botany and general scientific thinking were part of the fare. The botanical curriculum was printed: it was rather heavy with morphology and technical terms.
The botany taught in this school had effects throughout Britain, because important people at the centre, such as Prince AlbertPrince AlbertPrince Albert was the husband and consort of Queen Victoria.Prince Albert may also refer to:-Royalty:*Prince Albert Edward or Edward VII of the United Kingdom , son of Albert and Victoria...
and Lyon Playfair kept in touch and rightly regarded Henslow as an authority on the subject. - 2. Adult education in the Village. The Hitcham Labourers' and Mechanics' Horticultural Society was the vehicle used by Henslow to 'improve' the labouring and agricultural workers in the village and its surrounds. Competitions, shows and excursions were the attractions, and the intent was practical, to improve agriculture by improving the parishioners. Again Henslow made use of gifts and facilities provided by his friends.
- 3. Tackling the farmers. Surprising to us now, in those days the farmers were something of an obstacle to progress. They had not yet caught on to the advances made by Justus von LiebigJustus von LiebigJustus von Liebig was a German chemist who made major contributions to agricultural and biological chemistry, and worked on the organization of organic chemistry. As a professor, he devised the modern laboratory-oriented teaching method, and for such innovations, he is regarded as one of the...
in Germany, who began to apply chemistry to the needs of agriculture. Despite this, Henslow pressed on with ideas about field experiments which would try out various fertilisers and measure the resulting product. Questions such as "Should gypsum be added to manure heaps to fix the ammonia?" were proposed, no doubt to much muttering sotto voceSotto voceSotto voce means intentionally lowering one's voice for emphasis. The speaker gives the impression of uttering involuntarily a truth which may surprise, shock, or offend...
, and head-shaking from the farmers. It is only fair to add that Henslow did eventually get a good deal of help and acceptance for his ideas. - 4. Museums. The big town of Ipswich is twelve miles from Hitcham. As a result of his Cambridge experiences, Henslow believed in the value of museums as vehicles for education. The museum at IpswichIpswich MuseumIpswich Museum is a registered museum of culture, history and natural heritage located on High Street in Ipswich, the County Town of the English county of Suffolk...
, which was established in 1847, owed much to Henslow, who was elected President in 1850. The museum was based on natural history, construed in the broadest sense. A conflict between the Curator, a Dr Clarke, and the "vile and disorderly mob that contaminates our room on public nights" with their "obscene conversations [and] indelicate and blasphemous retorts" reminds us that delivering education to the people can be a challenging undertaking!
Alongside this work he remained an inquiring scientist at heart. In 1843 he discovered nodules of coprolitic
Coprolite
A coprolite is fossilized animal dung. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour rather than morphology. The name is derived from the Greek words κοπρος / kopros meaning 'dung' and λιθος / lithos meaning 'stone'. They...
origin in the Red Crag
Red Crag Formation
The Red Crag Formation is a series of marine deposits at the base of the Pleistocene in Suffolk and Essex. This material rests on an erosion surface of Cretaceous to Palaeogene rocks...
at Felixstowe
Felixstowe
Felixstowe is a seaside town on the North Sea coast of Suffolk, England. The town gives its name to the nearby Port of Felixstowe, which is the largest container port in the United Kingdom and is owned by Hutchinson Ports UK...
in Suffolk, and two years later he called attention to those also in the Cambridge Greensand
Cambridge Greensand
The Cambridge Greensand is a geological formation in England whose strata date back to the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Vertebrate paleofauna:...
and remarked that they might be of use in agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
. Although Henslow derived no benefit, these discoveries led to the establishment of the phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
industry in Suffolk and Cambridgeshire
Cambridgeshire
Cambridgeshire is a county in England, bordering Lincolnshire to the north, Norfolk to the northeast, Suffolk to the east, Essex and Hertfordshire to the south, and Bedfordshire and Northamptonshire to the west...
; and the works proved lucrative until the introduction of foreign phosphates.
Henslow died on 16 May 1861 at Hitcham.
Family
Henslow married Harriet Jenyns (1797–1857), daughter of George Leonard Jenyns and sister of Leonard Jenyns on 16 December 1823. Their eldest daughter Frances Harriet married Joseph Dalton HookerJoseph Dalton Hooker
Sir Joseph Dalton Hooker OM, GCSI, CB, MD, FRS was one of the greatest British botanists and explorers of the 19th century. Hooker was a founder of geographical botany, and Charles Darwin's closest friend...
. Their sons included George Henslow (1835–1925), who became the Royal Horticultural Society
Royal Horticultural Society
The Royal Horticultural Society was founded in 1804 in London, England as the Horticultural Society of London, and gained its present name in a Royal Charter granted in 1861 by Prince Albert...
’s Professor of Botany.
Further reading
- Henslow, John Stevens. (1856). A Dictionary of Botanical Terms. Groombridge (reissued by Cambridge University PressCambridge University PressCambridge University Press is the publishing business of the University of Cambridge. Granted letters patent by Henry VIII in 1534, it is the world's oldest publishing house, and the second largest university press in the world...
, 2009; ISBN 9781108001311) - Henslow, John Stevens. (1846). The Teaching of Science in Cambridge. Metcalfe and Palmer (reissued by Cambridge University PressCambridge University PressCambridge University Press is the publishing business of the University of Cambridge. Granted letters patent by Henry VIII in 1534, it is the world's oldest publishing house, and the second largest university press in the world...
, 2009; ISBN 9781108002004) - Henslow, John Stevens. (1835). The Principles of Descriptive and Physiological Botany. Longman, Rees, Orme, Brown & Green (reissued by Cambridge University PressCambridge University PressCambridge University Press is the publishing business of the University of Cambridge. Granted letters patent by Henry VIII in 1534, it is the world's oldest publishing house, and the second largest university press in the world...
, 2009; ISBN 9781108001861) - Henslow, John Stevens. (1823). A Syllabus of a Course of Lectures on Mineralogy. Deighton (reissued by Cambridge University PressCambridge University PressCambridge University Press is the publishing business of the University of Cambridge. Granted letters patent by Henry VIII in 1534, it is the world's oldest publishing house, and the second largest university press in the world...
, 2009; ISBN 9781108002011) - Nora Barlow (ed). 1967. Darwin and Henslow: The Growth of an Idea. Letters, 1831–1860. Murray, London.
- S.J. Plunkett 2002. Ipswich Museum Moralities in the 1840s and 1850s, in C. Harper-Bill (ed) East Anglia's History: studies in honour of Norman Scarfe Boydell, Woodbridge 2002, 309-332.
- Jean Russell-Gebbett 1977. Henslow of Hicham, botanist, educationalist and clergyman. Lavenham.
- S.M. Walters and E. A. Stow 2002. Darwin's Mentor. Cambridge University Press. ISBN 0-521-59146-5
- Image source: Portraits of the Honorary Members of the Ipswich Museum (Portfolio of 60 lithographs by T.H. Maguire) George Ransome, Ipswich, 1846–1852.