John Dalton

From Wikipedia, the free encyclopedia

John Dalton
Born	6 September 1766 Eaglesfield, Cumberland, England
Died	27 July 1844 (aged 77) Manchester, England
Notable students	James Prescott Joule
Known for	Atomic theory, Law of Multiple Proportions, Dalton's Law of Partial Pressures, Daltonism
Influences	John Gough
Notable awards	Royal Medal (1826)
Author abbrev. (botany)	Jn.Dalton
Signature

John Dalton FRS (6 September 1766 – 27 July 1844) was an English chemist, meteorologist and physicist. He is best known for his pioneering work in the development of modern atomic theory, and his research into colour blindness (sometimes referred to as Daltonism, in his honour).

Early life

John Dalton was born into a Quaker family at Eaglesfield, near Cockermouth, Cumberland, England.^[1] The son of a weaver, he joined his older brother Jonathan at age 15 in running a Quaker school in Kendal, about forty five miles away. Around 1790 Dalton seems to have considered taking up law or medicine, but his projects were not met with encouragement from his relatives – Dissenters were barred from attending or teaching at English universities – and he remained at Kendal until, in the spring of 1793, he moved to Manchester. Mainly through John Gough, a blind philosopher and polymath to whose informal instruction he owed much of his scientific knowledge, Dalton was appointed teacher of mathematics and natural philosophy at the "New College" in Manchester, a dissenting academy. He remained in that position until 1800, when the college's worsening financial situation led him to resign his post and begin a new career in Manchester as a private tutor for mathematics and natural philosophy.

Dalton's early life was highly influenced by a prominent Eaglesfield Quaker named Elihu Robinson,^[2] a competent meteorologist and instrument maker, who got him interested in problems of mathematics and meteorology. During his years in Kendal, Dalton contributed solutions of problems and questions on various subjects to The Ladies' Diary and the Gentleman's Diary, and in 1787 he began to keep a meteorological diary in which, during the succeeding 57 years, he entered more than 200,000 observations.^[3] He also rediscovered George Hadley's theory of atmospheric circulation (now known as the Hadley cell) around this time.^[4] Dalton's first publication was Meteorological Observations and Essays (1793), which contained the seeds of several of his later discoveries. However, in spite of the originality of his treatment, little attention was paid to them by other scholars. A second work by Dalton, Elements of English Grammar, was published in 1801.

Colour blindness

In 1794, shortly after his arrival in Manchester, Dalton was elected a member of the Manchester Literary and Philosophical Society, the "Lit & Phil", and a few weeks later he communicated his first paper on "Extraordinary facts relating to the vision of colours", in which he postulated that shortage in colour perception was caused by discoloration of the liquid medium of the eyeball. In fact, a shortage of colour perception in some people had not even been formally described or officially noticed until Dalton wrote about his own.^{[citation needed]} Since both he and his brother were colour blind, he recognized that this condition must be hereditary.^[5]

Although Dalton's theory lost credence in his own lifetime, the thorough and methodical nature of his research into his own visual problem was so broadly recognized that Daltonism became a common term for colour blindness.^[6] Examination of his preserved eyeball in 1995 demonstrated that Dalton actually had a less common kind of colour blindness, deuteroanopia, in which medium wavelength sensitive cones are missing (rather than functioning with a mutated form of their pigment, as in the most common type of colour blindness, deuteroanomaly).^[5] Besides the blue and purple of the spectrum he was able to recognize only one colour, yellow, or, as he says in his paper,

that part of the image which others call red appears to me little more than a shade or defect of light. After that the orange, yellow and green seem one colour which descends pretty uniformly from an intense to a rare yellow, making what I should call different shades of yellow

This paper was followed by many others on diverse topics on rain and dew and the origin of springs, on heat, the colour of the sky, steam, the auxiliary verbs and participles of the English language and the reflection and refraction of light.

Measuring Mountains in the Lake District

Dalton regularly holidayed in the Lake District where his study of meteorology involved a lot of climbing the fells: until the advent of aeroplanes and weather balloons, the only way to make measurements of temperature, humidity, etc. at altitude was to climb a mountain. The altitude achieved was estimated using a barometer. This meant that, until the Ordnance Survey started publishing their maps for the Lake District in the 1860s, Dalton was one of the few sources of such information.^[7] Dalton was often accompanied in the fells by Jonathan Otley, who became both assistant and friend. Otley was one of the few other authorities on the heights of the various mountains in the Lake District at the time.^[8]

Atomic theory

External video

Profiles in Chemistry:How John Dalton's meteorological studies led to the discovery of atoms on YouTube, Chemical Heritage Foundation

In 1800, Dalton became a secretary of the Manchester Literary and Philosophical Society, and in the following year he orally presented an important series of papers, entitled "Experimental Essays" on the constitution of mixed gases; on the pressure of steam and other vapours at different temperatures, both in a vacuum and in air; on evaporation; and on the thermal expansion of gases. These four essays were published in the Memoirs of the Lit & Phil in 1802.

The second of these essays opens with the striking remark,

There can scarcely be a doubt entertained respecting the reducibility of all elastic fluids of whatever kind, into liquids; and we ought not to despair of effecting it in low temperatures and by strong pressures exerted upon the unmixed gases further.

After describing experiments to ascertain the pressure of steam at various points between 0 and 100 °C (32 and 212 °F), Dalton concluded from observations on the vapour pressure of six different liquids, that the variation of vapour pressure for all liquids is equivalent, for the same variation of temperature, reckoning from vapour of any given pressure.

In the fourth essay he remarks,^[9]

I see no sufficient reason why we may not conclude that all elastic fluids under the same pressure expand equally by heat and that for any given expansion of mercury, the corresponding expansion of air is proportionally something less, the higher the temperature. It seems, therefore, that general laws respecting the absolute quantity and the nature of heat are more likely to be derived from elastic fluids than from other substances.

Gas laws

Joseph Louis Gay-Lussac

Jacques Alexandre César Charles, 1820

He thus enunciated Gay-Lussac's law or J.A.C. Charles's law, published in 1802 by Joseph Louis Gay-Lussac. In the two or three years following the reading of these essays, Dalton published several papers on similar topics, that on the absorption of gases by water and other liquids (1803), containing his law of partial pressures now known as Dalton's law.

The most important of all Dalton's investigations are those concerned with the atomic theory in chemistry, with which his name is inseparably associated. It has been proposed that this theory was suggested to him either by researches on ethylene (olefiant gas) and methane (carburetted hydrogen) or by analysis of nitrous oxide (protoxide of azote) and nitrogen dioxide (deutoxide of azote), both views resting on the authority of Thomas Thomson. However, a study of Dalton's own laboratory notebooks, discovered in the rooms of the Lit & Phil,^[10] concluded that so far from Dalton being led by his search for an explanation of the law of multiple proportions to the idea that chemical combination consists in the interaction of atoms of definite and characteristic weight, the idea of atoms arose in his mind as a purely physical concept, forced upon him by study of the physical properties of the atmosphere and other gases. The first published indications of this idea are to be found at the end of his paper on the absorption of gases already mentioned, which was read on 21
October 1803, though not published until 1805. Here he says:

Why does not water admit its bulk of every kind of gas alike? This question I have duly considered, and though I am not able to satisfy myself completely I am nearly persuaded that the circumstance depends on the weight and number of the ultimate particles of the several gases.

Atomic weights

Dalton proceeded to print his first published table of relative atomic weights. Six elements appear in this table, namely hydrogen, oxygen, nitrogen, carbon, sulfur, and phosphorus, with the atom of hydrogen conventionally assumed to weigh 1. Dalton provided no indication in this first paper how he had arrived at these numbers.^{[citation needed]} However, in his laboratory notebook under the date 6 September 1803^[11] there appears a list in which he sets out the relative weights of the atoms of a number of elements, derived from analysis of water, ammonia, carbon dioxide, etc. by chemists of the time.

It appears, then, that confronted with the problem of calculating the relative diameter of the atoms of which, he was convinced, all gases were made, he used the results of chemical analysis. Assisted by the assumption that combination always takes place in the simplest possible way, he thus arrived at the idea that chemical combination takes place between particles of different weights, and it was this which differentiated his theory from the historic speculations of the Greeks, such as Democritus and Lucretius.^{[citation needed]}

The extension of this idea to substances in general necessarily led him to the law of multiple proportions, and the comparison with experiment brilliantly confirmed his deduction.^[12] It may be noted that in a paper on the proportion of the gases or elastic fluids constituting the atmosphere, read by him in November 1802, the law of multiple proportions appears to be anticipated in the words: "The elements of oxygen may combine with a certain portion of nitrous gas or with twice that portion, but with no intermediate quantity", but there is reason to suspect that this sentence may have been added some time after the reading of the paper, which was not published until 1805.

Compounds were listed as binary, ternary, quaternary, etc. (molecules composed of two, three, four, etc. atoms) in the New System of Chemical Philosophy depending on the number of atoms a compound had in its simplest, empirical form.

He hypothesized the structure of compounds can be represented in whole number ratios. So, one atom of element X combining with one atom of element Y is a binary compound. Furthermore, one atom of element X combining with two elements of Y or vice versa, is a ternary compound. Many of the first compounds listed in the New System of Chemical Philosophy correspond to modern views, although many others do not.

Various atoms and molecules as depicted in John Dalton's A New System of Chemical Philosophy (1808).

Dalton used his own symbols to visually represent the atomic structure of compounds. These have made it in New System of Chemical Philosophy where Dalton listed a number of elements, and common compounds.

Main points of Dalton's atomic theory

1. Elements are made of extremely small particles called atoms.
2. Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties.
3. Atoms cannot be subdivided, created, or destroyed.
4. Atoms of different elements combine in simple whole-number ratios to form chemical compounds.
5. In chemical reactions, atoms are combined, separated, or rearranged.

Dalton proposed an additional "rule of greatest simplicity" that created controversy, since it could not be independently confirmed.

When atoms combine in only one ratio, "..it must be presumed to be a binary one, unless some cause appear to the contrary".

This was merely an assumption, derived from faith in the simplicity of nature. No evidence was then available to scientists to deduce how many atoms of each element combine to form compound molecules. But this or some other such rule was absolutely necessary to any incipient theory, since one needed an assumed molecular formula in order to calculate relative atomic weights. In any case, Dalton's "rule of greatest simplicity" caused him to assume that the formula for water was OH and ammonia was NH, quite different from our modern understanding (H₂O, NH₃).

Despite the uncertainty at the heart of Dalton's atomic theory, the principles of the theory survived. To be sure, the conviction that atoms cannot be subdivided, created, or destroyed into smaller particles when they are combined, separated, or rearranged in chemical reactions is inconsistent with the existence of nuclear fusion and nuclear fission, but such processes are nuclear reactions and not chemical reactions. In addition, the idea that all atoms of a given element are identical in their physical and chemical properties is not precisely true, as we now know that different isotopes of an element have slightly varying weights. However, Dalton had created a theory of immense power and importance. Indeed, Dalton's innovation was fully as important for the future of the science as Antoine Laurent Lavoisier's oxygen-based chemistry had been.

Later years

James Prescott Joule

Dalton communicated his atomic theory to Thomson who, by consent, included an outline of it in the third edition of his System of Chemistry (1807), and Dalton gave a further account of it in the first part of the first volume of his New System of Chemical Philosophy (1808). The second part of this volume appeared in 1810, but the first part of the second volume was not issued till 1827. This delay is not explained by any excess of care in preparation, for much of the matter was out of date and the appendix giving the author's latest views is the only portion of special interest. The second part of vol. ii. never appeared. For Rees's Cyclopaedia Dalton contributed articles on Chemistry and Meteorology, but the topics are not known.

He was president of the Lit & Phil from 1817 until his death, contributing 116 memoirs. Of these the earlier are the most important. In one of them, read in 1814, he explains the principles of volumetric analysis, in which he was one of the earliest workers. In 1840 a paper on the phosphates and arsenates, often regarded as a weaker work, was refused by the Royal Society, and he was so incensed that he published it himself. He took the same course soon afterwards with four other papers, two of which (On the quantity of acids, bases and salts in different varieties of salts and On a new and easy method of analysing sugar) contain his discovery, regarded by him as second in importance only to the atomic theory, that certain anhydrates, when dissolved in water, cause no increase in its volume, his inference being that the salt enters into the pores of the water.
James Prescott Joule was a famous pupil of Dalton.

Dalton's experimental method

Sir Humphry Davy, 1830 engraving based on the painting by Sir Thomas Lawrence (1769–1830)

As an investigator, Dalton was often content with rough and inaccurate instruments, though better ones were obtainable. Sir Humphry Davy described him as "a very coarse experimenter", who almost always found the results he required, trusting to his head rather than his hands. On the other hand, historians who have replicated some of his crucial experiments have confirmed Dalton's skill and precision.

In the preface to the second part of Volume I of his New System, he says he had so often been misled by taking for granted the results of others that he determined to write "as little as possible but what I can attest by my own experience", but this independence he carried so far that it sometimes resembled lack of receptivity. Thus he distrusted, and probably never fully accepted, Gay-Lussac's conclusions as to the combining volumes of gases. He held unconventional views on chlorine. Even after its elementary character had been settled by Davy, he persisted in using the atomic weights he himself had adopted, even when they had been superseded by the more accurate determinations of other chemists. He always objected to the chemical notation devised by Jöns Jakob Berzelius, although most thought that it was much simpler and more convenient than his own cumbersome system of circular symbols.

Public and personal life

Before he had propounded the atomic theory, he had already attained a considerable scientific reputation. In 1803, he was chosen to give a course of lectures on natural philosophy at the Royal Institution in London, where he delivered another course in 1809–1810. However, some witnesses reported that he was deficient in the qualities that make an attractive lecturer, being harsh and indistinct in voice, ineffective in the treatment of his subject, and singularly wanting in the language and power of illustration.

In 1810, Sir Humphry Davy asked him to offer himself as a candidate for the fellowship of the Royal Society, but Dalton declined, possibly for financial reasons. However, in 1822 he was proposed without his knowledge, and on election paid the usual fee. Six years previously he had been made a corresponding member of the French Académie des Sciences, and in 1830 he was elected as one of its eight foreign associates in place of Davy. In 1833, Earl Grey's government conferred on him a pension of £150, raised in 1836 to £300.

Dalton never married and had only a few close friends, all in all as a Quaker he lived a modest and unassuming life.^[13]

He lived for more than a quarter of a century with his friend the Rev. W. Johns (1771–1845), in George Street, Manchester, where his daily round of laboratory work and tuition was broken only by annual excursions to the Lake District and occasional visits to London. In 1822 he paid a short visit to Paris, where he met many distinguished resident scientists. He attended several of the earlier meetings of the British Association at York, Oxford, Dublin and Bristol. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1834.^[14]

Death and legacy

Bust of Dalton by Chantrey

Painting portrait of Dalton in later life

Dalton suffered a minor stroke in 1837, and a second one in 1838 left him with a speech impediment, though he remained able to do experiments. In May 1844 he had yet another stroke; on 26 July he recorded with trembling hand his last meteorological observation. On 27 July, in Manchester, Dalton fell from his bed and was found lifeless by his attendant. Approximately 40,000 people filed by his coffin as it was laid in state in the Manchester Town Hall.^[15] He was buried in Manchester in Ardwick cemetery. The cemetery is now a playing field, but pictures of the original grave are in published materials.^[16][17]

A bust of Dalton, by Chantrey, was publicly subscribed for^[18] and placed in the entrance hall of the Royal Manchester Institution. Chantrey also crafted a large statue of Dalton, now in the Manchester Town Hall. The statue was erected while Dalton was still alive and it has been said: "He is probably the only scientist who got a statue in his lifetime".^[15]

In honour of Dalton's work, many chemists and biochemists use the (as yet unofficial) unit dalton (abbreviated Da) to denote one atomic mass unit, or 1/12 the weight of a neutral atom of carbon-12. There is a John Dalton Street connecting Deansgate and Albert Square in the centre of Manchester.
Manchester Metropolitan University has a building named after John Dalton and occupied by the Faculty of Science and Engineering, in which the majority of its Science & Engineering lectures and classes take place. A statue is outside the John Dalton Building of the Manchester Metropolitan University in Chester Street which has been moved from Piccadilly. It was the work of William Theed (after Chantrey) and is dated 1855 (it was in Piccadilly until 1966).

The University of Manchester has a hall of residence called Dalton Hall; it also established two Dalton Chemical Scholarships, two Dalton Mathematical Scholarships, and a Dalton Prize for Natural History. There is a Dalton Medal awarded occasionally by the Manchester Literary and Philosophical Society (only 12 times altogether).

Dalton Township in southern Ontario was named for Dalton. It has, since 2001, been absorbed into the City of Kawartha Lakes. However the township name was used in a massive new park: Dalton Digby Wildlands Provincial Park, itself renamed since 2002.

A lunar crater has been named after Dalton. "Daltonism" became a common term for colour blindness and "Daltonien" is the actual French word for "colour blind".

The inorganic section of the UK's Royal Society of Chemistry is named after Dalton (Dalton Division), and the Society's academic journal for inorganic chemistry also bears his name (Dalton Transactions).

The name Dalton can often be heard in the halls of many Quaker schools, for example, one of the school houses in Coram House, the primary sector of Ackworth School, is called Dalton.

Much of his collected work was damaged during the bombing of the Manchester Literary and Philosophical Society on 24 December 1940. This event prompted Isaac Asimov to say, "John Dalton's records, carefully preserved for a century, were destroyed during the World War II bombing of Manchester. It is not only the living who are killed in war". The damaged papers are now in the John Rylands Library having been deposited in the university library by the Society.

Michael Faraday

From Wikipedia, the free encyclopedia

Michael Faraday
Michael Faraday, 1842
Born	22 September 1791 Newington Butts, England
Died	25 August 1867 (aged 75) Hampton Court, Middlesex, England
Residence	United Kingdom
Nationality	British
Fields	Physics and Chemistry
Institutions	Royal Institution
Known for	Faraday's law of induction Electrochemistry Faraday effect Faraday cage Faraday constant Faraday cup Faraday's laws of electrolysis Faraday paradox Faraday rotator Faraday-efficiency effect Faraday wave Faraday wheel Lines of force
Influences	Humphry Davy William Thomas Brande
Notable awards	Royal Medal (1835 & 1846) Copley Medal (1832 & 1838) Rumford Medal (1846) Albert Medal (1866)
Signature

External video

“Profiles in Chemistry: Michael Faraday” on YouTube, Chemical Heritage Foundation

Michael Faraday, FRS (22 September 1791 – 25 August 1867) was an English scientist who contributed to the fields of electromagnetism and electrochemistry. His main discoveries include those of electromagnetic induction, diamagnetism and electrolysis.

Although Faraday received little formal education, he was one of the most influential scientists in history. It was by his research on the magnetic field around a conductor carrying a direct current that Faraday established the basis for the concept of the electromagnetic field in physics. Faraday also established that magnetism could affect rays of light and that there was an underlying relationship between the two phenomena.^[1][2] He similarly discovered the principle of electromagnetic induction, diamagnetism, and the laws of electrolysis. His inventions of electromagnetic rotary devices formed the foundation of electric motor technology, and it was largely due to his efforts that electricity became practical for use in technology.

As a chemist, Faraday discovered benzene, investigated the clathrate hydrate of chlorine, invented an early form of the Bunsen burner and the system of oxidation numbers, and popularised terminology such as anode, cathode, electrode, and ion. Faraday ultimately became the first and foremost Fullerian Professor of Chemistry at the Royal Institution of Great Britain, a lifetime position.

Faraday was an excellent experimentalist who conveyed his ideas in clear and simple language; his mathematical abilities, however, did not extend as far as trigonometry or any but the simplest algebra. James Clerk Maxwell took the work of Faraday and others, and summarized it in a set of equations that is accepted as the basis of all modern theories of electromagnetic phenomena. On Faraday's uses of the lines of force, Maxwell wrote that they show Faraday "to have been in reality a mathematician of a very high order – one from whom the mathematicians of the future may derive valuable and fertile methods."^[3] The SI unit of capacitance, the Farad, is named in his honour.

Albert Einstein kept a picture of Faraday on his study wall, alongside pictures of Isaac Newton and James Clerk Maxwell.^[4] Physicist Ernest Rutherford stated; "When we consider the magnitude and extent of his discoveries and their influence on the progress of science and of industry, there is no honour too great to pay to the memory of Faraday, one of the greatest scientific discoverers of all time".^[5]

Personal life

Early life

Faraday was born in Newington Butts,^[6] which is now part of the London Borough of Southwark, but which was then a suburban part of Surrey.^[7] His family was not well off; his father, James, was a member of the Glassite sect of Christianity. James Faraday moved his wife and two children to London during the winter of 1790 from Outhgill in Westmorland, where he had been an apprentice to the village blacksmith.^[8] Michael was born the autumn of that year. The young Michael Faraday, who was the third of four children, having only the most basic school education, had to educate himself.^[9] At fourteen he became the apprentice to George Riebau, a local bookbinder and bookseller in Blandford Street.^[10] During his seven-year apprenticeship he read many books, including Isaac Watts' The Improvement of the Mind, and he enthusiastically implemented the principles and suggestions contained therein. At this time he also developed an interest in science, especially in electricity. Faraday was particularly inspired by the book Conversations on Chemistry by Jane Marcet.^[11][12]

Adult life

Portrait of Faraday in his late thirties

In 1812, at the age of twenty, and at the end of his apprenticeship, Faraday attended lectures by the eminent English chemist Humphry Davy of the Royal Institution and Royal Society, and John Tatum, founder of the City Philosophical Society. Many of the tickets for these lectures were given to Faraday by William Dance, who was one of the founders of the Royal Philharmonic Society. Faraday subsequently sent Davy a three-hundred-page book based on notes that he had taken during these lectures. Davy's reply was immediate, kind, and favourable. When Davy damaged his eyesight in an accident with nitrogen trichloride, he decided to employ Faraday as a secretary. When one of the Royal Institution's assistants, John Payne, was sacked, Sir Humphry Davy was asked to find a replacement, and appointed Faraday as Chemical Assistant at the Royal Institution on 1 March 1813.^[1]

In the class-based English society of the time, Faraday was not considered a gentleman. When Davy set out on a long tour of the continent in 1813–15, his valet did not wish to go. Instead, Faraday went as Davy's scientific assistant, and was asked to act as Davy's valet until a replacement could be found in Paris. Faraday was forced to fill the role of valet as well as assistant throughout the trip. Davy's wife, Jane Apreece, refused to treat Faraday as an equal (making him travel outside the coach, eat with the servants, etc.), and made Faraday so miserable that he contemplated returning to England alone and giving up science altogether. The trip did, however, give him access to the scientific elite of Europe and exposed him to a host of stimulating ideas.^[1]

Faraday married Sarah Barnard (1800–1879) on 12 June 1821.^[13] They met through their families at the Sandemanian church, and he confessed his faith to the Sandemanian congregation the month after they were married. They had no children.^[6]

Faraday was a devout Christian; his Sandemanian denomination was an offshoot of the Church of Scotland. Well after his marriage, he served as deacon and for two terms as an elder in the meeting house of his youth. His church was located at Paul's Alley in the Barbican. This meeting house was relocated in 1862 to Barnsbury Grove, Islington; this North London location was where Faraday served the final two years of his second term as elder prior to his resignation from that post.^[14][15] Biographers have noted that "a strong sense of the unity of God and nature pervaded Faraday's life and work."^[16]

Later life

Michael Faraday, ca. 1861

In June 1832, the University of Oxford granted Faraday a Doctor of Civil Law degree (honorary). During his lifetime, he was offered a knighthood in recognition for his services to science, which he turned down on religious grounds, believing it was against the word of the Bible to accumulate riches and pursue worldly reward, stating he preferred to remain "plain Mr Faraday to the end".^[17] He twice refused to become President of the Royal Society.^[18] He was elected a foreign member of the Royal Swedish Academy of Sciences in 1838, and was one of eight foreign members elected to the French Academy of Sciences in 1844.^[19]

Faraday suffered a nervous breakdown in 1839 but eventually returned to his electromagnetic investigations.^[20] In 1848, as a result of representations by the Prince Consort, Faraday was awarded a grace and favour house in Hampton Court in Middlesex, free of all expenses or upkeep. This was the Master Mason's House, later called Faraday House, and now No. 37 Hampton Court Road. In 1858 Faraday retired to live there.^[21]

When asked by the British government to advise on the production of chemical weapons for use in the Crimean War (1853–1856), Faraday refused to participate citing ethical reasons.^[22]

Faraday died at his house at Hampton Court on 25 August 1867, aged 75.^[23] He had previously turned down burial in Westminster Abbey, but he has a memorial plaque there, near Isaac Newton's tomb. Faraday was interred in the dissenters' (non-Anglican) section of Highgate Cemetery.

Scientific achievements

Chemistry

Faraday's earliest chemical work was as an assistant to Humphry Davy. Faraday was specifically involved in the study of chlorine; he discovered two new compounds of chlorine and carbon. He also conducted the first rough experiments on the diffusion of gases, a phenomenon that was first pointed out by John Dalton. The physical importance of this phenomenon was more fully revealed by Thomas Graham and Joseph Loschmidt. Faraday succeeded in liquefying several gases, investigated the alloys of steel, and produced several new kinds of glass intended for optical purposes. A specimen of one of these heavy glasses subsequently became historically important; when the glass was placed in a magnetic field Faraday determined the rotation of the plane of polarisation of light.
This specimen was also the first substance found to be repelled by the poles of a magnet.

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  Michael Faraday in his laboratory, ca. 1850s.
  
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  Michael Faraday's study at the Royal Institution.
  
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  Michael Faraday's flat at the Royal Institution.
  
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  Artist Harriet Jane Moore who documented Faraday's life in watercolours.
  

Faraday invented an early form of what was to become the Bunsen burner, which is in practical use in science laboratories around the world as a convenient source of heat.^[24][25] Faraday worked extensively in the field of chemistry, discovering chemical substances such as benzene (which he called bicarburet of hydrogen), and liquefying gases such as chlorine. The liquefying of gases helped to establish that gases are the vapours of liquids possessing a very low boiling point, and gave a more solid basis to the concept of molecular aggregation. In 1820 Faraday reported the first synthesis of compounds made from carbon and chlorine, C₂Cl₆ and C₂Cl₄, and published his results the following year.^[26][27][28] Faraday also determined the composition of the chlorine clathrate hydrate, which had been discovered by Humphry Davy in 1810.^[29][30] Faraday is also responsible for discovering the laws of electrolysis, and for popularizing terminology such as anode, cathode, electrode, and ion, terms proposed in large part by William Whewell.

Faraday was the first to report what later came to be called metallic nanoparticles. In 1847 he discovered that the optical properties of gold colloids differed from those of the corresponding bulk metal. This was probably the first reported observation of the effects of quantum size, and might be considered to be the birth of nanoscience.^[31]

Electricity and magnetism

Faraday is best known for his work regarding electricity and magnetism. His first recorded experiment was the construction of a voltaic pile with seven ha'penny coins, stacked together with seven disks of sheet zinc, and six pieces of paper moistened with salt water. With this pile he decomposed sulphate of magnesia (first letter to Abbott, 12 July 1812).

One of Faraday's 1831 experiments demonstrating induction. The liquid battery (right) sends an electric current through the small coil (A). When it is moved in or out of the large coil (B), its magnetic field induces a momentary voltage in the coil, which is detected by the galvanometer (G).

Electromagnetic rotation experiment of Faraday, ca. 1821^[32]

In 1821, soon after the Danish physicist and chemist Hans Christian Ørsted discovered the phenomenon of electromagnetism, Davy and British scientist William Hyde Wollaston tried, but failed, to design an electric motor.^[2] Faraday, having discussed the problem with the two men, went on to build two devices to produce what he called "electromagnetic rotation". One of these, now known as the homopolar motor, caused a continuous circular motion that was engendered by the circular magnetic force around a wire that extended into a pool of mercury wherein was placed a magnet; the wire would then rotate around the magnet if supplied with current from a chemical battery. These experiments and inventions formed the foundation of modern electromagnetic technology. In his excitement, Faraday published results without acknowledging his work with either Wollaston or Davy. The resulting controversy within the Royal Society strained his mentor relationship with Davy and may well have contributed to Faraday’s assignment to other activities, which consequently prevented his involvement in electromagnetic research for several years.^[33][34]
From his initial discovery in 1821, Faraday continued his laboratory work, exploring electromagnetic properties of materials and developing requisite experience. In 1824, Faraday briefly set up a circuit to study whether a magnetic field could regulate the flow of a current in an adjacent wire, but he found no such relationship.^[35] This experiment followed similar work conducted with light and magnets three years earlier that yielded identical results.^[36][37] During the next seven years, Faraday spent much of his time perfecting his recipe for optical quality (heavy) glass, borosilicate of lead,^[38] which he used in his future studies connecting light with magnetism.^[39] In his spare time, Faraday continued publishing his experimental work on optics and electromagnetism; he conducted correspondence with scientists whom he had met on his journeys across Europe with Davy, and who were also working on electromagnetism.^[40] Two years after the death of Davy, in 1831, he began his great series of experiments in which he discovered electromagnetic induction, recording in his laboratory diary on 28 October 1831 he was; "making many experiments with the great magnet of the Royal Society".^[41]

English chemists Michael Faraday (left) and John Daniell (right), credited as founders of electrochemistry today.

A diagram of Faraday's iron ring-coil apparatus

Faraday's breakthrough came when he wrapped two insulated coils of wire around an iron ring, and found that upon passing a current through one coil a momentary current was induced in the other coil.^[2] This phenomenon is now known as mutual induction.^[42] The iron ring-coil apparatus is still on display at the Royal Institution. In subsequent experiments, he found that if he moved a magnet through a loop of wire an electric current flowed in that wire. The current also flowed if the loop was moved over a stationary magnet. His demonstrations established that a changing magnetic field produces an electric field; this relation was modelled mathematically by James Clerk Maxwell as Faraday's law, which subsequently became one of the four Maxwell equations, and which have in turn evolved into the generalization known today as field theory. Faraday would later use the principles he had discovered to construct the electric dynamo, the ancestor of modern power generators and the electric motor.

In 1832, he completed a series of experiments aimed at investigating the fundamental nature of electricity; Faraday used "static", batteries, and "animal electricity" to produce the phenomena of electrostatic attraction, electrolysis, magnetism, etc. He concluded that, contrary to the scientific opinion of the time, the divisions between the various "kinds" of electricity were illusory. Faraday instead proposed that only a single "electricity" exists, and the changing values of quantity and intensity (current and voltage) would produce different groups of phenomena.^[2]

Near the end of his career, Faraday proposed that electromagnetic forces extended into the empty space around the conductor. This idea was rejected by his fellow scientists, and Faraday did not live to see the eventual acceptance of his proposition by the scientific community. Faraday's concept of lines of flux emanating from charged bodies and magnets provided a way to visualize electric and magnetic fields; that conceptual model was crucial for the successful development of the electromechanical devices that dominated engineering and industry for the remainder of the 19th century.

Diamagnetism

Michael Faraday holding a glass bar of the type he used in 1845 to show that magnetism can affect light in a dielectric material.^[43]

In 1845, Faraday discovered that many materials exhibit a weak repulsion from a magnetic field: a
phenomenon he termed diamagnetism.^[44]

Faraday also discovered that the plane of polarization of linearly polarized light can be rotated by the application of an external magnetic field aligned with the direction in which the light is moving. This is now termed the Faraday effect. He wrote in his notebook, "I have at last succeeded in illuminating a magnetic curve or line of force and in magnetising a ray of light".^[45]

Later on in his life, in 1862, Faraday used a spectroscope to search for a different alteration of light, the change of spectral lines by an applied magnetic field. The equipment available to him was, however, insufficient for a definite determination of spectral change. Pieter Zeeman later used an improved apparatus to study the same phenomenon, publishing his results in 1897 and receiving the 1902 Nobel Prize in Physics for his success. In both his 1897 paper^[46] and his Nobel acceptance speech,^[47] Zeeman made reference to Faraday's work.

Faraday cage

In his work on static electricity, Faraday's ice pail experiment demonstrated that the charge resided only on the exterior of a charged conductor, and exterior charge had no influence on anything enclosed within a conductor. This is because the exterior charges redistribute such that the interior fields due to them cancel. This shielding effect is used in what is now known as a Faraday cage.

Royal Institution and public service

Michael Faraday meets Father Thames, from Punch (21 July 1855)

Lighthouse lantern room from mid-1800s

Faraday had a long association with the Royal Institution of Great Britain. He was appointed Assistant Superintendent of the House of the Royal Institution in 1821.^[48] He was elected a member of the Royal Society in 1824.^[6] In 1825, he became Director of the Laboratory of the Royal Institution.^[48] Six years later, in 1833, Faraday became the first Fullerian Professor of Chemistry at the Royal Institution of Great Britain, a position to which he was appointed for life without the obligation to deliver lectures. His sponsor and mentor was John 'Mad Jack' Fuller, who created the position at the Royal Institution for Faraday.

Beyond his scientific research into areas such as chemistry, electricity, and magnetism at the Royal Institution, Faraday undertook numerous, and often time-consuming, service projects for private enterprise and the British government. This work included investigations of explosions in coal mines, being an expert witness in court, and along with two engineers from Chance Brothers c.1853, the preparation of high-quality optical glass, which was required by Chance for its lighthouses. In 1846, together with Charles Lyell, he produced a lengthy and detailed report on a serious explosion in the colliery at Haswell County Durham, which killed 95 miners. Their report was a meticulous forensic investigation and indicated that coal dust contributed to the severity of the explosion. The report should have warned coal owners of the hazard of coal dust explosions, but the risk was ignored for over 60 years until the Senghenydd Colliery Disaster of 1913.

As a respected scientist in a nation with strong maritime interests, Faraday spent extensive amounts of time on projects such as the construction and operation of light houses and protecting the bottoms of ships from corrosion. His workshop still stands at Trinity Buoy Wharf above the Chain and Buoy Store, next to London's only lighthouse where he carried out the first experiments in electric lighting for lighthouses.^[49]

Faraday was also active in what would now be called environmental science, or engineering. He investigated industrial pollution at Swansea and was consulted on air pollution at the Royal Mint. In July 1855, Faraday wrote a letter to The Times on the subject of the foul condition of the River Thames, which resulted in an oft-reprinted cartoon in Punch. (See also The Great Stink.)
Faraday assisted with the planning and judging of exhibits for the Great Exhibition of 1851 in London. He also advised the National Gallery on the cleaning and protection of its art collection, and served on the National Gallery Site Commission in 1857.^[50]

Education was another of Faraday's areas of service; he lectured on the topic in 1854 at the Royal Institution, and in 1862 he appeared before a Public Schools Commission to give his views on education in Great Britain. Faraday also weighed in negatively on the public's fascination with table-turning, mesmerism, and seances, and in so doing chastised both the public and the nation's educational system.^[51]

Michael Faraday delivering a Christmas Lecture at the Royal Institution in 1856.

Before his famous Christmas lectures, Faraday delivered chemistry lectures for the City Philosophical Society from 1816 to 1818 in order to refine the quality of his lectures.^[52] Between 1827 and 1860 at the Royal Institution in London, Faraday gave a series of nineteen Christmas lectures for young people, a series which continues today. The objective of Faraday’s Christmas lectures was to present science to the general public in the hopes of inspiring them and generating revenue for the Royal Institution. They were notable events on the social calendar among London’s gentry. Over the course of several letters to his close friend Benjamin Abbott, Faraday outlined his recommendations on the art of lecturing: Faraday wrote “a flame should be lighted at the commencement and kept alive with unremitting splendour to the end”.^[53] His lectures were joyful and juvenile, he delighted in filling soap bubbles with various gasses (in order to determine whether or not they are magnetic) in front of his audiences and marveled at the rich colors of polarized lights, but the lectures were also deeply philosophical. In his lectures he urged his audiences to consider the mechanics of his experiments: “you know very well that ice floats upon water . . . Why does the ice float? Think of that, and philosophise”.^[54] His subjects included:

• 1827 Chemistry
• 1829 Electricity
• 1832 Chemistry
• 1835 Electricity
• 1837 Chemistry
• 1841 The Rudiments of Chemistry
• 1843 First Principles of Electricity
• 1845 The Rudiments of Chemistry
• 1848 The Chemical History of a Candle
• 1851 Attractive Forces
• 1852 Chemistry
• 1853 Voltaic Electricity
• 1854 The Chemistry of Combustion
• 1855 The Distinctive Properties of the Common Metals
• 1856 Attractive Forces
• 1857 Static Electricity
• 1858 The Metallic Properties
• 1859 The Various Forces of Matter and their Relations to Each Other
• 1860 The Chemical History of a Candle

Commemorations

Michael Faraday statue in Savoy Place, London. Sculptor John Henry Foley RA.

A statue of Faraday stands in Savoy Place, London, outside the Institution of Engineering and Technology. Also in London, the Michael Faraday Memorial, designed by brutalist architect Rodney Gordon and completed in 1961, is at the Elephant & Castle gyratory system, near Faraday's birthplace at Newington Butts. Faraday School is located on Trinity Buoy Wharf where his workshop still stands above the Chain and Buoy Store, next to London's only lighthouse.^[55]

Faraday Gardens is a small park in Walworth, London, not far from his birthplace at Newington Butts. This park lies within the local council ward of Faraday in the London Borough of Southwark. Michael Faraday Primary school is situated on the Aylesbury Estate in Walworth.^[56]

A building at London South Bank University, which houses the institute's electrical engineering departments is named the Faraday Wing, due to its proximity to Faraday's birthplace in Newington Butts. A hall at Loughborough University was named after Faraday in 1960. Near the entrance to its dining hall is a bronze casting, which depicts the symbol of an electrical transformer, and inside there hangs a portrait, both in Faraday's honour. An eight-story building at the University of Edinburgh's science & engineering campus is named for Faraday, as is a recently built hall of accommodation at Brunel University, the main engineering building at Swansea University, and the instructional and experimental physics building at Northern Illinois University. The former UK Faraday Station in Antarctica was named after him.

Streets named for Faraday can be found in many British cities (e.g., London, Fife, Swindon, Basingstoke, Nottingham, Whitby, Kirkby, Crawley, Newbury, Swansea, Aylesbury and Stevenage) as well as in France (Paris), Germany (Berlin-Dahlem, Hermsdorf), Canada (Quebec; Deep River, Ontario; Ottawa, Ontario), and the United States (Reston, Virginia).

A Royal Society of Arts blue plaque, unveiled in 1876, commemorates Faraday at 48 Blandford Street in London's Marylebone district.^[57] From 1991 until 2001, Faraday's picture featured on the reverse of Series E £20 banknotes issued by the Bank of England. He was shown conducting a lecture at the Royal Institution with the magneto-electric spark apparatus.^[58] In 2002, Faraday was ranked number 22 in the BBC's list of the 100 Greatest Britons following a UK-wide vote.^[59]

The Faraday Institute for Science and Religion derives its name from the scientist, who saw his faith as integral to his scientific research. The logo of the Institute is also based on Faraday's discoveries. It was created in 2006 by a $2,000,000 grant from the John Templeton Foundation to carry out academic research, to foster understanding of the interaction between science and religion, and to engage public understanding in both these subject areas.^[60][61]

Faraday's life and contributions to electromagnetics was the principal topic of the tenth episode of the 2014 American science documentary series, Cosmos: A Spacetime Odyssey, which was broadcast on Fox and the National Geographic Channel.^[62]

Bibliography

Faraday's books, with the exception of Chemical Manipulation, were collections of scientific papers or transcriptions of lectures.^[63] Since his death, Faraday's diary has been published, as have several large volumes of his letters and Faraday's journal from his travels with Davy in 1813–1815.

• Faraday, Michael (1827). Chemical Manipulation, Being Instructions to Students in Chemistry. John Murray. 2nd ed. 1830, 3rd ed. 1842
• Faraday, Michael (1839, 1844). Experimental Researches in Electricity, vols. i. and ii.. Richard and John Edward Taylor. ; vol. iii. Richard Taylor and William Francis, 1855
• Faraday, Michael (1859). Experimental Researches in Chemistry and Physics. Taylor and Francis. ISBN 0-85066-841-7.
• Faraday, Michael (1861). W. Crookes, ed. A Course of Six Lectures on the Chemical History of a Candle. Griffin, Bohn & Co. ISBN 1-4255-1974-1.
• Faraday, Michael (1873). W. Crookes, ed. On the Various Forces in Nature. Chatto and Windus.
• Faraday, Michael (1932–1936). T. Martin, ed. Diary. ISBN 0-7135-0439-0. – published in eight volumes; see also the 2009 publication of Faraday's diary
• Faraday, Michael (1991). B. Bowers and L. Symons, ed. Curiosity Perfectly Satisfyed: Faraday's Travels in Europe 1813–1815. Institution of Electrical Engineers.
• Faraday, Michael (1991). F. A. J. L. James, ed. The Correspondence of Michael Faraday 1. INSPEC, Inc. ISBN 0-86341-248-3. – volume 2, 1993; volume 3, 1996; volume 4, 1999
• Faraday, Michael (2008). Alice Jenkins, ed. Michael Faraday's Mental Exercises: An Artisan Essay Circle in Regency London. Liverpool, UK: Liverpool University Press.
• Course of six lectures on the various forces of matter, and their relations to each other London; Glasgow: R. Griffin, 1860.
• The Liquefaction of Gases, Edinburgh: W. F. Clay, 1896.
• The letters of Faraday and Schoenbein 1836–1862. With notes, comments and references to contemporary letters London: Williams & Norgate 1899. (Digital edition by the University and State Library Düsseldorf)