John Dalton
Born	September 6, 1766(1766-09-06) Eaglesfield, near Cockermouth, Cumbria, England
Died	July 27, 1844 (aged 77) Manchester, England
Doctoral advisor	John Gough
Doctoral students	James Prescott Joule
Known for	Atomic Theory, Law of Multiple Proportions, Dalton's Law of Partial Pressures, Daltonism

John Dalton FRS (September 6, 1766 – July 27, 1844) was an English chemist, meteorologist and physicist. Events 3114 BC - According to the Proleptic Julian calendar the current era in the Maya Long Count Calendar started Year 1766 ( MDCCLXVI) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Cockermouth is a town within the Allerdale borough of Cumbria, England, and is so named because it is at the confluence of the River Cocker Boundaries and divisions Cumbria is neighboured by Northumberland, County Durham, North Yorkshire, Lancashire, and the Lieutenancy England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland Events 1214 - Battle of Bouvines: In France, Philip II of France defeats John of England. Year 1844 ( MDCCCXLIV) was a Leap year starting on Monday (link will display the full calendar of the Gregorian Calendar (or a Leap year England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland A doctorate is an Academic degree that indicates the highest level of academic achievement John Gough ( 17 January, 1757 28 July, 1825) was a blind English natural and experimental philosopher who is known for his own investigations James Prescott Joule FRS (ˈdʒuːl December 24, 1818 &ndash October 11, 1889) was an English Physicist This article focuses on the historical models of the atom For a history of the study of how atoms combine to form molecules see History of the molecule. In Chemistry, the law of multiple proportions is one of the basic laws and a major tool of chemical measurement ( Stoichiometry) In Chemistry and Physics, Dalton's law (also called Dalton's law of partial pressures) states that the total Pressure exerted by a Color blindness, a Color vision deficiency is the inability to perceive differences between some of the Colors that others can distinguish The Royal Society of London for the Improvement of Natural Knowledge, known simply as The Royal Society, is a Learned society for science that was founded in 1660 Events 3114 BC - According to the Proleptic Julian calendar the current era in the Maya Long Count Calendar started Year 1766 ( MDCCLXVI) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Events 1214 - Battle of Bouvines: In France, Philip II of France defeats John of England. Year 1844 ( MDCCCXLIV) was a Leap year starting on Monday (link will display the full calendar of the Gregorian Calendar (or a Leap year England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland A chemist is a Scientist trained in the Science of Chemistry. Meteorology (from Greek grc μετέωρος metéōros, "high in the sky" and grc -λογία -logia) is the Interdisciplinary A physicist is a Scientist who studies or practices Physics. Physicists study a wide range of physical phenomena in many branches of physics spanning 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). This article focuses on the historical models of the atom For a history of the study of how atoms combine to form molecules see History of the molecule. Color blindness, a Color vision deficiency is the inability to perceive differences between some of the Colors that others can distinguish

Early life

Dalton was born into a Quaker family at Eaglesfield, near Cockermouth in Cumbria, England. Cockermouth is a town within the Allerdale borough of Cumbria, England, and is so named because it is at the confluence of the River Cocker Boundaries and divisions Cumbria is neighboured by Northumberland, County Durham, North Yorkshire, Lancashire, and the Lieutenancy England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland The son of a weaver, he joined his older brother Jonathan at age 15 in running a Quaker school in nearby Kendal. 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. Law is a system of rules enforced through a set of Institutions used as an instrument to underpin civil obedience politics economics and society Medicine is the art and science of healing It encompasses a range of Health care practices evolved to maintain and restore Human Health by the English Dissenters were Christians who separated from the Church of England. Kendal is a Market town and Civil parish within the South Lakeland district of Cumbria, England. Mainly through John Gough, a blind philosopher and polymath from 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. John Gough ( 17 January, 1757 28 July, 1825) was a blind English natural and experimental philosopher who is known for his own investigations For the current in the 19th century German idealism see Naturphilosophie Natural philosophy or the philosophy of nature (from Harris Manchester College is one of the constituent colleges of the University of Oxford in the United Kingdom. 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, a competent meteorologist and instrument maker, who got him interested in problems of mathematics and meteorology. Meteorology (from Greek grc μετέωρος metéōros, "high in the sky" and grc -λογία -logia) is the Interdisciplinary During his years in Kendal, Dalton contributed solutions of problems and questions on various subjects to the Gentlemen's and Ladies' Diaries, and in 1787 he began to keep a meteorological diary in which, during the succeeding 57 years, he entered more than 200,000 observations. Meteorology (from Greek grc μετέωρος metéōros, "high in the sky" and grc -λογία -logia) is the Interdisciplinary For other uses of the term 'diary' see Diary (disambiguation. ^[1] 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

This image shows a number 44 or 49, but someone who is deuteranopic may not be able to see it.

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 discolouration of the liquid medium of the eyeball. The Manchester Literary and Philosophical Society is a Learned society in Manchester, England. Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain 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. 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. Color blindness, a Color vision deficiency is the inability to perceive differences between some of the Colors that others can distinguish 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). Color blindness, a Color vision deficiency is the inability to perceive differences between some of the Colors that others can distinguish Color blindness, a Color vision deficiency is the inability to perceive differences between some of the Colors that others can distinguish 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. Blue is a Colour, the Perception of which is evoked by Purple is a general term for the range of shades of Color occurring between Red and Blue. Yellow is the Color evoked by light that stimulates both the L and M (long and medium wavelength Cone cells of the Retina about equally Red is any of a number of similar Colors evoked by light consisting predominantly of the longest wavelengths of Light discernible by the human eye in the wavelength Light, or visible light, is Electromagnetic radiation of a Wavelength that is visible to the Human eye (about 400–700 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. The colour orange occurs Green is a Color, the perception of which is evoked by light having a spectrum dominated by energy with a Wavelength of roughly 520–570- nm.

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. Rain is Liquid precipitation. On Earth it is the condensation of atmospheric Water vapor into drops heavy enough to fall often making it to Formation Water will condense into droplets depending on the temperature A spring is a point where Groundwater flows out of the ground and is thus where the Aquifer surface meets the ground surface In Physics, heat, symbolized by Q, is Energy transferred from one body or system to another due to a difference in Temperature The sky is the part of the Atmosphere or of Outer space visible from the surface of any Astronomical object. Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. In Linguistics, an auxiliary (also called helping verb, helper verb, auxiliary verb, or verbal auxiliary) is a Verb functioning In Linguistics, a participle (from Latin participium, a Calque of Greek μετοχη "partaking" is a derivative of a non-finite English is a West Germanic language originating in England and is the First language for most people in the United Kingdom, the United States Reflection is the change in direction of a Wave front at an interface between two different media so that the wave front returns into the medium from which Refraction is the change in direction of a Wave due to a change in its Speed.

Atomic theory

In 1800 he 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. The Manchester Literary and Philosophical Society is a Learned society in Manchester, England. This page is about the physical properties of gas as a state of matter Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface A vapor or vapour (see Spelling differences) is a substance in the Gas phase at a Temperature lower than its Critical temperature Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature This vacuum means "absence of matter" or "an empty area or space" for the cleaning appliance see Vacuum cleaner. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Evaporation is the process by which Molecules in a Liquid state (e Thermal Expansion is the tendency of matter to change in Volume in response to a change in temperature 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 affecting it in low temperatures and by strong pressures exerted upon the unmixed gases further. Cryogenics is often used incorrectly to refer to Cryonics, cryopreserving humans or animals

After describing experiments to ascertain the pressure of steam at various points between 0° and 100°C (32° and 212°F), he 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. The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium

In the fourth essay he remarks,

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. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum 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. The expression Gay-Lussac's law is used for each of the two relationships named after the French chemist Joseph Louis Gay-Lussac and which concern the properties of Gases A. C. Charles's law, published in 1802 by Joseph Louis Gay-Lussac. In Thermodynamics and Physical chemistry, Charles's law is a gas law and specific instance of the Ideal gas law, which states that Joseph Louis Gay-Lussac (also Louis Joseph Gay-Lussac, December 6, 1778 – May 9, 1850) was a French chemist 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. In Chemistry and Physics, Dalton's law (also called Dalton's law of partial pressures) states that the total Pressure exerted by a

The most important of all Dalton's investigations are those concerned with the atomic theory in chemistry, with which his name is inseparably associated. This article focuses on the historical models of the atom For a history of the study of how atoms combine to form molecules see History of the molecule. 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. Structure This Hydrocarbon has four Hydrogen Atoms bound to a pair of Carbon atoms that are connected by a Double bond. Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. Nitrous oxide, commonly known as " laughing gas," is a Chemical compound with the Chemical formula N 2 O. Nitrogen dioxide is the Chemical compound with the formula N[[Oxygen O]]2 Thomas Thomson FRS ( 12 April, 1773 &ndash 2 July, 1852) was a Scottish Chemist whose writings contributed However, a study of Dalton's own laboratory notebooks, discovered in the rooms of the Lit & Phil,^[2] 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. In Chemistry, the law of multiple proportions is one of the basic laws and a major tool of chemical measurement ( Stoichiometry) Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five This page is about the physical properties of gas as a state of matter 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 October 21, 1803, though not published until 1805. Events 1512 - Martin Luther joins the theological faculty of the University of Wittenberg. 1803 ( MDCCCIII) was a Common year starting on Saturday (link will display the full calendar of the Gregorian calendar (or a 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

He proceeds to print his first published table of relative atomic weights. The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass 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. However, in his laboratory notebook under the date 6 September 1803^[3] 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. Water is a common Chemical substance that is essential for the survival of all known forms of Life. Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single 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. Analytical chemistry is the study of the Chemical composition of natural and artificial Materials. 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. The term ancient Greece refers to the period of Greek history lasting from the Greek Dark Ages ca Democritus ( Greek:) was a pre-Socratic Greek Materialist Philosopher (born at Abdera in Thrace ca Titus Lucretius Carus (ca 99 BC- ca 55 BC was a Roman Poet and Philosopher.

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. ^[4] 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 till 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.

Five main points of Dalton's Atomic Theory

• Elements are made of tiny particles called atoms. History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny
• All atoms of a given element are identical.
• The atoms of a given element are different from those of any other element; the atoms of different elements can be distinguished from one another by their respective relative weights.
• Atoms of one element can combine with atoms of other elements to form chemical compounds; a given compound always has the same relative numbers of types of atoms. A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass.
• Atoms cannot be created, divided into smaller particles, nor destroyed in the chemical process; a chemical reaction simply changes the way atoms are grouped together. A chemical reaction is a process that always results in the interconversion of Chemical substances The substance or substances initially involved in a chemical reaction are called

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. Water is a common Chemical substance that is essential for the survival of all known forms of Life. Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor

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 Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus Nuclear fission is the splitting of the nucleus of an atom into parts (lighter nuclei) often producing Free neutrons and other smaller nuclei which may 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. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides 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

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.

Dalton 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. Titration is a common laboratory method of Quantitative chemical analysis that is used to determine the unknown Concentration of a known Reactant 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. A phosphate, an Inorganic chemical, is a salt of Phosphoric acid. Arsenic (ˈɑrsənɪk is a Chemical element that has the symbol As and Atomic number of 33 The Royal Society of London for the Improvement of Natural Knowledge, known simply as The Royal Society, is a Learned society for science that was founded in 1660 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. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are In Chemistry, a base is most commonly thought of as an aqueous substance that can accept Protons This refers to the Brønsted-Lowry theory of acids and Salt is a Dietary mineral composed primarily of Sodium chloride that is essential for Animal life but toxic to most land plants Sugar is a class of edible Crystalline substances mainly Sucrose, Lactose, and Fructose. In Chemistry, an anhydride is a compound that can be considered as derived from another compound by subtracting the molecules of water. Porosity is a measure of the void spaces in a material and is measured as a fraction between 0–1 or as a Percentage between 0–100%

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. Sir Humphry Davy 1st Baronet FRS MRIA (17 December 1778 &ndash 29 May 1829 was a British Chemist and inventor 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. Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and 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. Friherre Jöns Jacob Berzelius (20 August 1779 &ndash 7 August 1848 was a Swedish chemist

Public life

Before he had propounded the atomic theory, he had already attained a considerable scientific reputation. In 1804 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. The Royal Institution of Great Britain is an organization devoted to scientific education and research based in London. London ( ˈlʌndən is the capital and largest urban area in the United Kingdom. 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 Humphrey Davy asked him to offer himself as a candidate for the fellowship of the Royal Society, but Dalton declined, possibly for financial reasons. Sir Humphry Davy 1st Baronet FRS MRIA (17 December 1778 &ndash 29 May 1829 was a British Chemist and inventor The Royal Society of London for the Improvement of Natural Knowledge, known simply as The Royal Society, is a Learned society for science that was founded in 1660 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. This article is about the country For a topic outline on this subject see List of basic France topics. The French Academy of Sciences ( French: Académie des sciences) is a Learned society, founded in 1666 by Louis XIV at the

In 1833 Earl Grey's government conferred on him a pension of £150, raised in 1836 to £300. Charles Grey 2nd Earl Grey, KG, PC (13 March 1764 &ndash 17 July 1845 known as Viscount Howick between 1806 and 1807 was a British The Pound Sterling ( symbol £; ISO code: GBP) subdivided into 100 pence (singular penny) is the Currency

Dalton never married and had only a few close friends. 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. The Lake District, also known as The Lakes or Lakeland, is a rural area in North West England. In 1822 he paid a short visit to Paris, where he met many distinguished resident scientists. Paris (ˈpærɨs in English; in French) is the Capital of France and the country's largest city He attended several of the earlier meetings of the British Association at York, Oxford, Dublin and Bristol. York ( is an historic Walled city sited at the confluence of the rivers Ouse and Foss in North Yorkshire, England. Oxford is currently bidding for the 2010 Wikimania Conference Oxford () is a city, and the County town of Oxfordshire, Dublin (ˈdʌblɨn/ /ˈdʊblɨn or /ˈdʊbəlɪn/, bˠalʲə aːha klʲiəh or cliə(ɸ is both the largest city and capital of Ireland. Bristol ( ˈbrɪstəl is a city, Unitary authority and ceremonial county in South West England, west of London

Death and legacy

Bust of Dalton by Chantrey

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. Sir Francis Legatt Chantrey ( April 7, 1782 &ndash November 25, 1841) was an English sculptor of the Georgian era A stroke is the rapidly developing loss of brain functions due to a disturbance in the blood vessels supplying blood to the brain In May 1844 he had yet another stroke; on July 26 he recorded with trembling hand his last meteorological observation. On July 27, in Manchester, Dalton fell from his bed and was found lifeless by his attendant.

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. ^{[5] [6]}

A bust of Dalton, by Chantrey, was publicly subscribed for^[7] and placed in the entrance hall of the Royal Manchester Institution. Sir Francis Legatt Chantrey ( April 7, 1782 &ndash November 25, 1841) was an English sculptor of the Georgian era The Royal Manchester Institution was an English Learned society founded on 1 October 1823 at a public meeting held in the Exchange Room by Chantrey also crafted a large statue of Dalton, now in the Manchester Town Hall. Manchester Town Hall is a building in Manchester, England that houses Manchester City Council.

In honour of Dalton's work, many chemists and biochemists use the (as of yet unofficial) unit dalton (abbreviated Da) to denote one atomic mass unit, or 1/12 the weight of a neutral atom of carbon-12. The unified atomic mass unit ( u) or Dalton ( Da) or sometimes universal mass unit, is an unit of Mass used to express

The University of Manchester established two Dalton Chemical Scholarships, two Dalton Mathematical Scholarships, and a Dalton Prize for Natural History.

In his book The 100, Michael H. Hart ranks Dalton as the 32nd most influential person in history. The 100 A Ranking of the Most Influential Persons in History is a 1978 book by Michael H Michael H Hart (born April 28, 1932 in New York City) is an Astrophysicist who has also written three books on History and controversial

A lunar crater has been named after Dalton. Dalton is a lunar Impact crater that is located near the western limb of the Moon 's near side

See also

• daltonism
• Democritus
• atomic mass unit (dalton) - the atomic mass unit

References

1. ^ Smith, R. Color blindness, a Color vision deficiency is the inability to perceive differences between some of the Colors that others can distinguish Democritus ( Greek:) was a pre-Socratic Greek Materialist Philosopher (born at Abdera in Thrace ca The unified atomic mass unit ( u) or Dalton ( Da) or sometimes universal mass unit, is an unit of Mass used to express Angus (1856). Memoir of John Dalton and History of the Atomic Theory. London: H. Bailliere, 279. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  
2. ^ Roscoe, Henry E. ; Arthur Harden (1896). A New View of the Origin of Dalton's Atomic Theory. London: Macmillan. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  
3. ^ Laboratory notebook in ibid. , p. 248
4. ^ Roscoe, Henry E. ; Arthur Harden (1896). A New View of the Origin of Dalton's Atomic Theory. London: Macmillan, 50 – 51. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  
5. ^ Patterson, Elizabeth C. (1970). John Dalton and the Atomic Theory. Garden City, New York: Anchor.  
6. ^ Elliott, T. Lenton (1953). "John Dalton's Grave". Journal of Chemical Education 30: 569.  
7. ^ Millington, John Price (1906). John Dalton. London: J. M. Dent & Company, 201 – 208. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  

Bibliography

Statue of Dalton by Chantrey

• Greenaway, Frank (1966). John Dalton and the Atom. Ithaca, New York: Cornell University Press.  

• Henry, William C. (1854). Memoirs of the Life and Scientific Researches of John Dalton. London: Cavendish Society. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  

• Hunt, D. M. ; Dulai, K. S. ; Bowmaker, J. K. & Mollon, J. D. (1995), “The Chemistry of John Dalton's Color Blindness”, Science 267: 984 – 988, <http://www.sciencemag.org/cgi/content/abstract/267/5200/984>. Retrieved on 24 December 2007 

• Lonsdale, Henry (1874). The Worthies of Cumberland: John Dalton. George Routledge and Sons: George. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  

• Millington, John Price (1906). John Dalton. London: J. M. Dent & Company. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  

• Patterson, Elizabeth C. (1970). John Dalton and the Atomic Theory. Garden City, New York: Anchor.  

• Rocke, A. J. (2005). "In Search of El Dorado: John Dalton and the Origins of the Atomic Theory". Social Research 72: 125 – 158.  

• Roscoe, Henry E. (1895). John Dalton and the Rise of Modern Chemistry. London: Macmillan. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  

• Roscoe, Henry E. ; Arthur Harden (1896). A New View of the Origin of Dalton's Atomic Theory. London: Macmillan. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  

• Smith, R. Angus (1856). Memoir of John Dalton and History of the Atomic Theory. London: H. Bailliere. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  

• Smyth, A. L. (1998). John Dalton, 1766-1844: A Bibliography of Works by and About Him, With an Annotated List of His Surviving Apparatus and Personal Effects.  - Original edition published by Manchester University Press in 1966

• Thackray, Arnold (1972). John Dalton: Critical Assessments of His Life and Science. Harvard University Press. ISBN 0-674-47525-9.  

External links

• Dalton, John (1834). Meteorological Observations and Essays, 2, Manchester: Harrison and Crosfield. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  

• Dalton, John (1893). Foundations of the Atomic Theory. Edinburgh: William F. Clay. Retrieved on 2007-12-24. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes  - Alembic Club reprint with some of Dalton's papers, along with some by William Hyde Wollaston and Thomas Thomson