Editing Isaac Newton (section)

== Later life ==
{{Main article|Later life of Isaac Newton}}

=== Royal Mint ===
[[File:Newton 25.jpg|thumb|upright|Isaac Newton in old age in 1712, portrait by [[Sir James Thornhill]]]]
In the 1690s, Newton wrote a number of [[religious tracts]] dealing with the literal and symbolic interpretation of the Bible. A manuscript Newton sent to [[John Locke]] in which he disputed the fidelity of [[1 John 5:7]]—the [[Johannine Comma]]—and its fidelity to the original manuscripts of the New Testament, remained unpublished until 1785.<ref>{{Cite web |title=John Locke Manuscripts&nbsp;– Chronological Listing: 1690 |url=http://www.libraries.psu.edu/tas/locke/mss/c1690.html |url-status=live |archive-url=https://web.archive.org/web/20170709035722/https://www.libraries.psu.edu/tas/locke/mss/c1690.html |archive-date=9 July 2017 |access-date=20 January 2013 |website=psu.edu}}; and John C. Attig, [http://www.libraries.psu.edu/tas/locke/bib/ch5c.html#01160 John Locke Bibliography&nbsp;— Chapter 5, Religion, 1751–1900] {{Webarchive|url=https://web.archive.org/web/20121112070820/http://www.libraries.psu.edu/tas/locke/bib/ch5c.html#01160 |date=12 November 2012 }}</ref>

Newton was also a member of the [[Parliament of England]] for [[Cambridge University (UK Parliament constituency)|Cambridge University]] in 1689 and 1701, but according to some accounts his only comments were to complain about a cold draught in the chamber and request that the window be closed.{{sfn|White|1997|p=232}} He was, however, noted by Cambridge diarist [[Abraham de la Pryme]] to have rebuked students who were frightening locals by claiming that a house was haunted.<ref>{{Cite news |last=Sawer |first=Patrick |date=6 September 2016 |title=What students should avoid during fresher's week (100&nbsp;years ago and now) |work=The Daily Telegraph |url=https://www.telegraph.co.uk/news/2016/09/06/what-students-should-avoid-during-freshers-week-100-years-ago-an/ |url-status=live |url-access=subscription |access-date=7 September 2016 |archive-url=https://ghostarchive.org/archive/20220110/https://www.telegraph.co.uk/news/2016/09/06/what-students-should-avoid-during-freshers-week-100-years-ago-an/ |archive-date=10 January 2022}}{{cbignore}}</ref>

Newton moved to London to take up the post of warden of the [[Royal Mint]] during the reign of [[William III of England|King William III]] in 1696, a position that he had obtained through the patronage of [[Charles Montagu, 1st Earl of Halifax]], then [[Chancellor of the Exchequer]]. He took charge of England's great recoining, trod on the toes of Lord Lucas, Governor of the Tower, and secured the job of deputy [[comptroller]] of the temporary Chester branch for Edmond Halley. Newton became perhaps the best-known [[Master of the Mint]] upon the death of [[Thomas Neale]] in 1699, a position he held for the last 30&nbsp;years of his life.<ref name="Mint">{{Cite episode |title=Isaac Newton: Physicist And&nbsp;... Crime Fighter? |url=https://www.npr.org/templates/story/story.php?storyId=105012144 |access-date=1 August 2014 |series=Science Friday |network=NPR |transcript=Transcript |transcript-url=https://www.npr.org/templates/transcript/transcript.php?storyId=105012144 |air-date=5 June 2009 |archive-date=1 November 2014 |archive-url=https://web.archive.org/web/20141101074330/http://www.npr.org/templates/story/story.php?storyId=105012144 |url-status=live}}</ref>{{sfn|Levenson |2010}} These appointments were intended as [[sinecure]]s, but Newton took them seriously. He retired from his Cambridge duties in 1701, and exercised his authority to reform the currency and punish [[Methods of coin debasement|clippers]] and counterfeiters.

As Warden, and afterwards as Master, of the Royal Mint, Newton estimated that 20&nbsp;percent of the coins taken in during the [[Great Recoinage of 1696]] were [[Counterfeit money|counterfeit]]. Counterfeiting was [[High treason in the United Kingdom|high treason]], punishable by the felon being [[hanged, drawn and quartered]]. Despite this, convicting even the most flagrant criminals could be extremely difficult, but Newton proved equal to the task.{{sfn|White|1997|p=259}} 

Disguised as a [[:wikt:habitué|habitué]] of bars and taverns, he gathered much of that evidence himself.{{sfn|White|1997|p=267}} For all the barriers placed to prosecution, and separating the branches of government, [[English law]] still had ancient and formidable customs of authority. Newton had himself made a [[justice of the peace]] in all the [[home counties]]. A draft letter regarding the matter is included in Newton's personal first edition of ''Philosophiæ Naturalis Principia Mathematica'', which he must have been amending at the time.<ref>{{Cite web |last=Newton |first=Isaac |title=Philosophiæ Naturalis Principia Mathematica |url=http://cudl.lib.cam.ac.uk/view/PR-ADV-B-00039-00001/ |url-status=live |archive-url=https://web.archive.org/web/20120108031556/http://cudl.lib.cam.ac.uk/view/PR-ADV-B-00039-00001/ |archive-date=8 January 2012 |access-date=10 January 2012 |publisher=Cambridge University Digital Library |pages=265–66}}</ref> Then he conducted more than 100&nbsp;cross-examinations of witnesses, informers, and suspects between June 1698 and Christmas 1699. He successfully prosecuted 28&nbsp;coiners, including serial counterfeiter [[William Chaloner]], who was subsequently hanged.{{sfn|Westfall|2007|p=73}}

Beyond prosecuting counterfeiters, he improved minting technology and reduced the standard deviation of the weight of guineas from 1.3 grams to 0.75 grams. Starting in 1707, Newton introduced the practice of testing a small sample of coins, a pound in weight, in the [[Trial of the Pyx|trial of the pyx]], which helped to reduce the size of admissible error. He ultimately saved the Treasury a then £41,510, roughly £3 million in 2012,<ref>{{Cite web |last=Aron |first=Jacob |date=2012-05-29 |title=Newton saved the UK economy £10 million |url=https://www.newscientist.com/article/dn21856-newton-saved-the-uk-economy-10-million/ |access-date=2025-01-25 |website=New Scientist |language=en-US}}</ref> with his improvements lasting until the 1770s, thereby increasing the accuracy of British coinage.<ref name=":3">{{Cite journal |last=Belenkiy |first=Ari |date=1 February 2013 |title=The Master of the Royal Mint: How Much Money did Isaac Newton Save Britain? |url=https://academic.oup.com/jrsssa/article/176/2/481/7077810 |journal=Journal of the Royal Statistical Society Series A: Statistics in Society |volume=176 |issue=2 |pages=481–498 |doi=10.1111/j.1467-985X.2012.01037.x |issn=0964-1998 |hdl-access=free |hdl=10.1111/j.1467-985X.2012.01037.x}}</ref>

Newton's activities at the Mint influenced rising scientific and commercial interests in fields such as [[numismatics]], [[geology]], [[mining]], [[metallurgy]], and [[metrology]] in the early 18th century.<ref name=":24">{{Cite journal |last=Marples |first=Alice |date=20 September 2022 |title=The science of money: Isaac Newton's mastering of the Mint |url=https://royalsocietypublishing.org/doi/10.1098/rsnr.2021.0033 |journal=Notes and Records: The Royal Society Journal of the History of Science |volume=76 |issue=3 |pages=507–525 |doi=10.1098/rsnr.2021.0033 |issn=0035-9149}}</ref>

[[File:ENG COA Newton.svg|thumb|upright|[[Coat of arms]] of the Newton family of [[Great Gonerby]], Lincolnshire, afterwards used by Sir Isaac<ref>{{Cite book |last=Wagner |first=Anthony |url=https://archive.org/details/historicheraldry0000wagn/page/85 |title=Historic Heraldry of Britain |publisher=Phillimore |year=1972 |isbn=978-0-85033-022-9 |edition=2nd |location=London and Chichester |page=[https://archive.org/details/historicheraldry0000wagn/page/85 85] |author-link=Anthony Wagner}}; and {{cite book|title=Genealogical Memoranda Relating to the Family of Newton|place=London|publisher=Taylor and Co.|year=1871|url=https://archive.org/details/genealogicalmemo00inlond }}</ref>]]

Newton was made president of the [[Royal Society]] in 1703 and an associate of the French [[French Academy of Sciences|Académie des Sciences]]. In his position at the Royal Society, Newton made an enemy of [[John Flamsteed]], the [[Astronomer Royal]], by prematurely publishing Flamsteed's ''Historia Coelestis Britannica'', which Newton had used in his studies.{{sfn|White|1997|p=317}}

=== Knighthood ===
In April 1705, Queen Anne [[Knight Bachelor|knighted]] Newton during a royal visit to Trinity College, Cambridge. The knighthood is likely to have been motivated by political considerations connected with the [[1705 English general election|parliamentary election in May 1705]], rather than any recognition of Newton's scientific work or services as Master of the Mint.<ref>"The Queen's 'great Assistance' to Newton's election was his knighting, an honor bestowed not for his contributions to science, nor for his service at the Mint, but for the greater glory of party politics in the election of 1705." {{harvnb|Westfall|1994|p=245}}</ref> Newton was the second scientist to be knighted, after [[Francis Bacon]].<ref>{{Cite web |title=This Month in Physics History |url=https://www.aps.org/archives/publications/apsnews/201103/physicshistory.cfm |access-date=2025-03-06 |website=www.aps.org |language=en}}</ref>

As a result of a report written by Newton on 21 September 1717 to the Lords Commissioners of His Majesty's Treasury, the bimetallic relationship between gold coins and silver coins was changed by royal proclamation on 22 December 1717, forbidding the exchange of gold guineas for more than 21&nbsp;silver shillings.<ref>[http://www.pierre-marteau.com/editions/1701-25-mint-reports/report-1717-09-25.html ''On the Value of Gold and Silver in European Currencies and the Consequences on the Worldwide Gold- and Silver-Trade''] {{Webarchive|url=https://web.archive.org/web/20170406191205/http://www.pierre-marteau.com/editions/1701-25-mint-reports/report-1717-09-25.html |date=6 April 2017 }}, Sir Isaac Newton, 21 September 1717; [https://archive.org/details/numismaticser1v05royauoft "By The King, A Proclamation Declaring the Rates at which Gold shall be current in Payments"]. ''Royal Numismatic Society''. '''V'''. April 1842&nbsp;– January 1843.</ref> This inadvertently resulted in a silver shortage as silver coins were used to pay for imports, while exports were paid for in gold, effectively moving Britain from the [[silver standard]] to its first [[gold standard]]. It is a matter of debate as to whether he intended to do this or not.<ref>{{Cite journal |last=Fay |first=C.&nbsp;R. |date=1 January 1935 |title=Newton and the Gold Standard |journal=Cambridge Historical Journal |volume=5 |issue=1 |pages=109–17 |doi=10.1017/S1474691300001256 |jstor=3020836}}</ref> It has been argued that Newton viewed his work at the Mint as a continuation of his alchemical work.<ref>{{Cite news |date=12 September 2006 |title=Sir Isaac Newton's Unpublished Manuscripts Explain Connections He Made Between Alchemy and Economics |publisher=Georgia Tech Research News |url=http://gtresearchnews.gatech.edu/newsrelease/newton.htm |url-status=dead |access-date=30 July 2014 |archive-url=https://archive.today/20130217100410/http://gtresearchnews.gatech.edu/newsrelease/newton.htm |archive-date=17 February 2013}}</ref>

Newton was invested in the [[South Sea Company]] and lost at least £10,000, and plausibly more than £20,000 (£4.4&nbsp;million in 2020<ref>Eric W. Nye, [https://www.uwyo.edu/numimage/currency.htm Pounds Sterling to Dollars: Historical Conversion of Currency] {{Webarchive|url=https://web.archive.org/web/20210815124946/https://www.uwyo.edu/numimage/Currency.htm |date=15 August 2021 }}. Retrieved: 5 October 2020</ref>) when it collapsed in around 1720. Since he was already rich before the bubble, he still died rich, at estate value around £30,000.<ref>{{Cite journal |last=Odlyzko |first=Andrew |date=2019-03-20 |title=Newton's financial misadventures in the South Sea Bubble |url=https://royalsocietypublishing.org/doi/10.1098/rsnr.2018.0018 |journal=Notes and Records: The Royal Society Journal of the History of Science |language=en |volume=73 |issue=1 |pages=29–59 |doi=10.1098/rsnr.2018.0018 |issn=0035-9149}}</ref>

Toward the end of his life, Newton took up residence at [[Cranbury Park]], near [[Winchester]], with his niece and her husband, until his death.<ref name="Yonge6">{{Cite web |last=Yonge |first=Charlotte&nbsp;M. |author-link=Charlotte M. Yonge |year=1898 |title=Cranbury and Brambridge |url=http://www.online-literature.com/charlotte-yonge/john-keble/6/ |url-status=live |archive-url=https://web.archive.org/web/20081208223436/http://www.online-literature.com/charlotte-yonge/john-keble/6/ |archive-date=8 December 2008 |access-date=23 September 2009 |website=[[John Keble]]'s Parishes&nbsp;– Chapter 6 |publisher=online-literature.com}}</ref> His half-niece, [[Catherine Barton]],{{sfn|Westfall|1980|p=44}} served as his hostess in social affairs at his house on [[Jermyn Street]] in London; he was her "very loving Uncle",{{sfn|Westfall|1980|p=595}} according to his letter to her when she was recovering from [[smallpox]].

=== Death ===
[[File:PSM V69 D480 Death mask of isaac newton.png|alt=Isaac Newton's death mask|thumb|upright|Death mask of Newton, photographed {{circa|1906}}]]
Newton died in his sleep in London on 20 March 1727 ([[Old Style and New Style dates|NS]] 31 March 1727).{{efn|name=OSNS}} He was given a ceremonial funeral, attended by nobles, scientists, and philosophers, and was buried in [[Westminster Abbey]] among kings and queens. He was the first scientist to be buried in the abbey.<ref>{{London Gazette |issue=6569 |date=1 April 1727 |page=7 }}</ref> [[Voltaire]] may have been present at his funeral.<ref>Dobre and Nyden suggest that there is no clear evidence that Voltaire was present; see p. 89 of {{Cite book |last1=Dobre |first1=Mihnea |title=Cartesian Empiricism |last2=Nyden |first2=Tammy |publisher=Springer |year=2013 |isbn=978-94-007-7690-6}}</ref> A bachelor, he had divested much of his estate to relatives during his last years, and died [[intestacy|intestate]].<ref name="Newton, Isaac (1642–1727)" /> His papers went to [[John Conduitt]] and [[Catherine Barton]].<ref name="Mann">{{Cite magazine |last=Mann |first=Adam |date=14 May 2014 |title=The Strange, Secret History of Isaac Newton's Papers |url=https://www.wired.com/2014/05/newton-papers-q-and-a/ |url-access=limited |url-status=live |archive-url=https://web.archive.org/web/20170911221912/https://www.wired.com/2014/05/newton-papers-q-and-a/ |archive-date=11 September 2017 |access-date=25 April 2016 |magazine=Wired}}</ref>

Shortly after his death, a plaster [[death mask]] was moulded of Newton. It was used by [[Flemings|Flemish]] sculptor [[John Michael Rysbrack]] in making a sculpture of Newton.<ref>{{Cite web |title=Newton's Death Mask |url=https://huntington.org/verso/newtons-death-mask |access-date=7 August 2023 |website=The Huntington |date=2 August 2011 |first1=John |last1=Vining |archive-date=7 August 2023 |archive-url=https://web.archive.org/web/20230807122527/https://huntington.org/verso/newtons-death-mask |url-status=live }}</ref> It is now held by the [[Royal Society]].<ref>{{Cite web |title=Death mask of Isaac Newton |url=https://pictures.royalsociety.org/image-rs-8492 |access-date=7 August 2023 |website=Royal Society Picture Library |archive-date=7 August 2023 |archive-url=https://web.archive.org/web/20230807122526/https://pictures.royalsociety.org/image-rs-8492 |url-status=live }}</ref>

Newton's hair was posthumously examined and found to contain [[mercury (element)|mercury]], probably resulting from his alchemical pursuits. [[Mercury poisoning]] could explain Newton's eccentricity in late life.<ref name="Newton, Isaac (1642–1727)" />