Editing Latent heat (section)

=== Background ===

==== Evaporative cooling ====
[[File:William_Cullen_(cropped).jpg|thumb|183x183px|William Cullen]]
In 1748, an account was published in ''The Edinburgh Physical and Literary Essays'' of an experiment by the Scottish physician and chemist [[William Cullen]]. Cullen had used an [[air pump]] to lower the pressure in a container with [[diethyl ether]]. No heat was withdrawn from the ether, yet the ether boiled, but its temperature decreased.<ref name=":0">{{Cite journal |last=West |first=J.B. |author-link=John B. West |date=2014-06-15 |title=Joseph Black, carbon dioxide, latent heat, and the beginnings of the discovery of the respiratory gases |url=https://www.physiology.org/doi/10.1152/ajplung.00020.2014 |journal=American Journal of Physiology-Lung Cellular and Molecular Physiology |language=en |volume=306 |issue=12 |pages=L1057–L1063 |doi=10.1152/ajplung.00020.2014 |pmid=24682452 |issn=1040-0605}}</ref><ref name=":1">{{Cite book |last=Ramsay |first=W. |author-link=William Ramsay |url=https://books.google.com/books?id=micIAAAAIAAJ&pg=PA38 |title=The life and letters of Joseph Black, M.D. |publisher=Constable |year=1918 |pages=38–39}}</ref> And in 1758, on a warm day in [[Cambridge]], England, [[Benjamin Franklin]] and fellow scientist [[John Hadley (chemist)|John Hadley]] experimented by continually wetting the ball of a mercury [[thermometer]] with ether and using [[bellows]] to evaporate the ether.<ref>{{cite web |title=The Writings of Benjamin Franklin: London, 1757–1775 |url=http://www.historycarper.com/resources/twobf3/letter1.htm |url-status=dead |archive-url=https://web.archive.org/web/20110128075748/http://www.historycarper.com/resources/twobf3/letter1.htm |archive-date=January 28, 2011 |access-date=September 14, 2010 |publisher=Historycarper.com}}</ref> With each subsequent [[evaporation]], the thermometer read a lower temperature, eventually reaching {{convert|7|F}}. Another thermometer showed that the room temperature was constant at {{convert|65|F}}. In his letter ''[[Evaporative cooler|Cooling by Evaporation]]'', Franklin noted that, "One may see the possibility of freezing a man to death on a warm summer's day."<ref>{{Cite web |title=Founders Online: From Benjamin Franklin to John Lining, 17 June 1758 |url=http://founders.archives.gov/documents/Franklin/01-08-02-0023 |access-date=June 30, 2021 |website=founders.archives.gov |language=en}}</ref>