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Available in 19 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-19" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">19 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D9%85%D9%83%D8%A7%D9%81%D8%A6_%D9%85%D9%8A%D9%83%D8%A7%D9%86%D9%8A%D9%83%D9%8A_%D9%84%D9%84%D8%AD%D8%B1%D8%A7%D8%B1%D8%A9" title="مكافئ ميكانيكي للحرارة – Arabic" lang="ar" hreflang="ar" data-title="مكافئ ميكانيكي للحرارة" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%A4%E0%A6%BE%E0%A6%AA%E0%A7%87%E0%A6%B0_%E0%A6%AF%E0%A6%BE%E0%A6%A8%E0%A7%8D%E0%A6%A4%E0%A7%8D%E0%A6%B0%E0%A6%BF%E0%A6%95_%E0%A6%B8%E0%A6%AE%E0%A6%A4%E0%A6%BE" title="তাপের যান্ত্রিক সমতা – Bangla" lang="bn" hreflang="bn" data-title="তাপের যান্ত্রিক সমতা" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/W%C3%A4rme%C3%A4quivalent" title="Wärmeäquivalent – German" lang="de" hreflang="de" data-title="Wärmeäquivalent" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Equivalente_mec%C3%A1nico_del_calor" title="Equivalente mecánico del calor – Spanish" lang="es" hreflang="es" data-title="Equivalente mecánico del calor" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D9%85%D8%B9%D8%A7%D8%AF%D9%84_%D9%85%DA%A9%D8%A7%D9%86%DB%8C%DA%A9%DB%8C_%DA%AF%D8%B1%D9%85%D8%A7" title="معادل مکانیکی گرما – Persian" lang="fa" hreflang="fa" data-title="معادل مکانیکی گرما" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EC%97%B4%EC%9D%98_%EC%9D%BC%EB%8B%B9%EB%9F%89" title="열의 일당량 – Korean" lang="ko" hreflang="ko" data-title="열의 일당량" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D5%8B%D5%A5%D6%80%D5%B4%D5%B8%D6%82%D5%A9%D5%B5%D5%A1%D5%B6_%D5%B4%D5%A5%D5%AD%D5%A1%D5%B6%D5%AB%D5%AF%D5%A1%D5%AF%D5%A1%D5%B6_%D5%B0%D5%A1%D5%B4%D5%A1%D6%80%D5%AA%D5%A5%D6%84" title="Ջերմության մեխանիկական համարժեք – Armenian" lang="hy" hreflang="hy" data-title="Ջերմության մեխանիկական համարժեք" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%8A%E0%A4%B7%E0%A5%8D%E0%A4%AE%E0%A4%BE_%E0%A4%95%E0%A4%BE_%E0%A4%AF%E0%A4%BE%E0%A4%82%E0%A4%A4%E0%A5%8D%E0%A4%B0%E0%A4%BF%E0%A4%95_%E0%A4%A4%E0%A5%81%E0%A4%B2%E0%A5%8D%E0%A4%AF%E0%A4%BE%E0%A4%82%E0%A4%95" title="ऊष्मा का यांत्रिक तुल्यांक – Hindi" lang="hi" hreflang="hi" data-title="ऊष्मा का यांत्रिक तुल्यांक" data-language-autonym="हिन्दी" data-language-local-name="Hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Equivalente_meccanico_del_calore" title="Equivalente meccanico del calore – Italian" lang="it" hreflang="it" data-title="Equivalente meccanico del calore" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/A_h%C5%91_mechanikai_egyen%C3%A9rt%C3%A9ke" title="A hő mechanikai egyenértéke – Hungarian" lang="hu" hreflang="hu" data-title="A hő mechanikai egyenértéke" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E7%86%B1%E3%81%AE%E4%BB%95%E4%BA%8B%E5%BD%93%E9%87%8F" title="熱の仕事当量 – Japanese" lang="ja" hreflang="ja" data-title="熱の仕事当量" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Mekanisk_varmeteori" title="Mekanisk varmeteori – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Mekanisk varmeteori" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Equivalente_mec%C3%A2nico_do_calor" title="Equivalente mecânico do calor – Portuguese" lang="pt" hreflang="pt" data-title="Equivalente mecânico do calor" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Echivalentul_mecanic_al_caloriei" title="Echivalentul mecanic al caloriei – Romanian" lang="ro" hreflang="ro" data-title="Echivalentul mecanic al caloriei" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%9C%D0%B5%D1%85%D0%B0%D0%BD%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%B8%D0%B9_%D1%8D%D0%BA%D0%B2%D0%B8%D0%B2%D0%B0%D0%BB%D0%B5%D0%BD%D1%82_%D1%82%D0%B5%D0%BF%D0%BB%D0%BE%D1%82%D1%8B" title="Механический эквивалент теплоты – Russian" lang="ru" hreflang="ru" data-title="Механический эквивалент теплоты" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/L%C3%A4mm%C3%B6n_mekaaninen_ekvivalentti" title="Lämmön mekaaninen ekvivalentti – Finnish" lang="fi" hreflang="fi" data-title="Lämmön mekaaninen ekvivalentti" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-ta mw-list-item"><a href="https://ta.wikipedia.org/wiki/%E0%AE%B5%E0%AF%86%E0%AE%AA%E0%AF%8D%E0%AE%AA%E0%AE%A4%E0%AF%8D%E0%AE%A4%E0%AE%BF%E0%AE%A9%E0%AF%8D_%E0%AE%AA%E0%AF%8A%E0%AE%B1%E0%AE%BF%E0%AE%AE%E0%AF%81%E0%AE%B1%E0%AF%88%E0%AE%9A%E0%AF%8D_%E0%AE%9A%E0%AE%AE%E0%AE%B5%E0%AE%B2%E0%AF%81" title="வெப்பத்தின் பொறிமுறைச் சமவலு – Tamil" lang="ta" hreflang="ta" data-title="வெப்பத்தின் பொறிமுறைச் சமவலு" data-language-autonym="தமிழ்" data-language-local-name="Tamil" class="interlanguage-link-target"><span>தமிழ்</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9C%D0%B5%D1%85%D0%B0%D0%BD%D1%96%D1%87%D0%BD%D0%B8%D0%B9_%D0%B5%D0%BA%D0%B2%D1%96%D0%B2%D0%B0%D0%BB%D0%B5%D0%BD%D1%82_%D1%82%D0%B5%D0%BF%D0%BB%D0%BE%D1%82%D0%B8" title="Механічний еквівалент теплоти – Ukrainian" lang="uk" hreflang="uk" data-title="Механічний еквівалент теплоти" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E7%83%AD%E5%8A%9F%E5%BD%93%E9%87%8F" title="热功当量 – Chinese" lang="zh" hreflang="zh" data-title="热功当量" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q901795#sitelinks-wikipedia" title="Edit interlanguage links" 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.thumbinner{width:100%!important;box-sizing:border-box;max-width:none!important;align-items:center}.mw-parser-output .tmulti .trow{justify-content:center}.mw-parser-output .tmulti .tsingle{float:none!important;max-width:100%!important;box-sizing:border-box;text-align:center}.mw-parser-output .tmulti .tsingle .thumbcaption{text-align:left}.mw-parser-output .tmulti .trow>.thumbcaption{text-align:center}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .tmulti .multiimageinner img{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .tmulti .multiimageinner img{background-color:white}}</style><div class="thumb tmulti tright"><div class="thumbinner multiimageinner" style="width:342px;max-width:342px"><div class="trow"><div class="tsingle" style="width:169px;max-width:169px"><div class="thumbimage" style="height:206px;overflow:hidden"><span typeof="mw:File"><a href="/wiki/File:James_Prescott_Joule._Photogravure_after_G._Patten._Wellcome_M0011245.jpg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/James_Prescott_Joule._Photogravure_after_G._Patten._Wellcome_M0011245.jpg/167px-James_Prescott_Joule._Photogravure_after_G._Patten._Wellcome_M0011245.jpg" decoding="async" width="167" height="206" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/James_Prescott_Joule._Photogravure_after_G._Patten._Wellcome_M0011245.jpg/251px-James_Prescott_Joule._Photogravure_after_G._Patten._Wellcome_M0011245.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/48/James_Prescott_Joule._Photogravure_after_G._Patten._Wellcome_M0011245.jpg/334px-James_Prescott_Joule._Photogravure_after_G._Patten._Wellcome_M0011245.jpg 2x" data-file-width="2917" data-file-height="3602" /></a></span></div><div class="thumbcaption"><a href="/wiki/James_Prescott_Joule" title="James Prescott Joule">James Prescott Joule</a></div></div><div class="tsingle" style="width:169px;max-width:169px"><div class="thumbimage" style="height:206px;overflow:hidden"><span typeof="mw:File"><a href="/wiki/File:Julius_Robert_von_Mayer_1878.jpg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/7/70/Julius_Robert_von_Mayer_1878.jpg/167px-Julius_Robert_von_Mayer_1878.jpg" decoding="async" width="167" height="207" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/70/Julius_Robert_von_Mayer_1878.jpg/251px-Julius_Robert_von_Mayer_1878.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/70/Julius_Robert_von_Mayer_1878.jpg/334px-Julius_Robert_von_Mayer_1878.jpg 2x" data-file-width="878" data-file-height="1086" /></a></span></div><div class="thumbcaption"><a href="/wiki/Julius_Robert_von_Mayer" class="mw-redirect" title="Julius Robert von Mayer">Julius Robert von Mayer</a></div></div></div></div></div> <p>In the <a href="/wiki/History_of_science" title="History of science">history of science</a>, the <b>mechanical equivalent of heat</b> states that <a href="/wiki/Motion_(physics)" class="mw-redirect" title="Motion (physics)">motion</a> and <a href="/wiki/Heat" title="Heat">heat</a> are mutually interchangeable and that in every case, a given amount of <a href="/wiki/Work_(thermodynamics)" title="Work (thermodynamics)">work</a> would generate the same amount of heat, provided the work done is totally converted to heat energy. The mechanical equivalent of heat was a <a href="/wiki/Concept" title="Concept">concept</a> that had an important part in the development and acceptance of the <a href="/wiki/Conservation_of_energy" title="Conservation of energy">conservation of energy</a> and the establishment of the science of <a href="/wiki/Thermodynamics" title="Thermodynamics">thermodynamics</a> in the 19th century. Its independent and simultaneous discovery by <a href="/wiki/James_Prescott_Joule" title="James Prescott Joule">James Prescott Joule</a> and by <a href="/wiki/Julius_von_Mayer" title="Julius von Mayer">Julius Robert von Mayer</a> led to a <a href="/wiki/Priority_dispute" class="mw-redirect" title="Priority dispute">priority dispute</a>. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="History_and_priority_dispute">History and priority dispute</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mechanical_equivalent_of_heat&action=edit&section=1" title="Edit section: History and priority dispute"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure typeof="mw:File/Thumb"><a href="/wiki/File:Joule%27s_Apparatus_(Harper%27s_Scan).png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c3/Joule%27s_Apparatus_%28Harper%27s_Scan%29.png/300px-Joule%27s_Apparatus_%28Harper%27s_Scan%29.png" decoding="async" width="300" height="247" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c3/Joule%27s_Apparatus_%28Harper%27s_Scan%29.png/450px-Joule%27s_Apparatus_%28Harper%27s_Scan%29.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c3/Joule%27s_Apparatus_%28Harper%27s_Scan%29.png/600px-Joule%27s_Apparatus_%28Harper%27s_Scan%29.png 2x" data-file-width="1684" data-file-height="1387" /></a><figcaption>Joule's apparatus for measuring the mechanical equivalent of heat in which the "<a href="/wiki/Work_(thermodynamics)" title="Work (thermodynamics)">work</a>" of the falling weight is converted into the "<a href="/wiki/Heat" title="Heat">heat</a>" of agitation in the water.</figcaption></figure> <p><a href="/wiki/Benjamin_Thompson" title="Benjamin Thompson">Benjamin Thompson</a>, Count Rumford, had observed the frictional heat generated by boring cannon at the arsenal in Munich, <a href="/wiki/Electorate_of_Bavaria" title="Electorate of Bavaria">Bavaria, circa 1797</a> Rumford immersed a cannon barrel in water and arranged for a specially blunted boring tool. He showed that the water could be boiled within roughly two and a half hours and that the supply of frictional heat was seemingly inexhaustible. </p><p>Based on his experiments, he published "<a href="/wiki/An_Experimental_Enquiry_Concerning_the_Source_of_the_Heat_which_is_Excited_by_Friction" class="mw-redirect" title="An Experimental Enquiry Concerning the Source of the Heat which is Excited by Friction">An Experimental Enquiry Concerning the Source of the Heat which is Excited by Friction</a>", (1798), <i><a href="/wiki/Philosophical_Transactions_of_the_Royal_Society" title="Philosophical Transactions of the Royal Society">Philosophical Transactions of the Royal Society</a></i> p. 102. This scientific paper provided a substantial challenge to established theories of heat and began the 19th century revolution in thermodynamics. The experiment inspired the work of James Prescott Joule in the 1840s. Joule's more exact measurements on equivalence were pivotal in establishing the <a href="/wiki/Kinetic_theory_of_gases" title="Kinetic theory of gases">kinetic theory</a> at the expense of the <a href="/wiki/Caloric_theory" title="Caloric theory">caloric theory</a>. The idea that heat and work are equivalent was also proposed by <a href="/wiki/Julius_von_Mayer" title="Julius von Mayer">Julius Robert von Mayer</a> in 1842 in the leading German physics journal and independently by James Prescott Joule in 1843, in the leading British physics journal. Similar work was carried out by <a href="/wiki/Ludwig_A._Colding" title="Ludwig A. Colding">Ludwig A. Colding</a> in 1840–1843, though Colding's work was little known outside his native Denmark. </p><p>A collaboration between <a href="/wiki/Nicolas_Cl%C3%A9ment" title="Nicolas Clément">Nicolas Clément</a> and <a href="/wiki/Nicolas_L%C3%A9onard_Sadi_Carnot" title="Nicolas Léonard Sadi Carnot">Sadi Carnot</a> in the 1820s had some related thinking near the same lines.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> In 1845, Joule published a paper entitled "The Mechanical Equivalent of Heat", in which he specified a numerical value for the amount of mechanical work required to produce a unit of heat. In particular Joule had experimented on the amount of mechanical work generated by friction needed to raise the <a href="/wiki/Temperature" title="Temperature">temperature</a> of a <a href="/wiki/Pound_(mass)" title="Pound (mass)">pound</a> of <a href="/wiki/Water" title="Water">water</a> by one degree <a href="/wiki/Fahrenheit" title="Fahrenheit">Fahrenheit</a> and found a consistent value of 778.24 <a href="/wiki/Foot_pound_force" class="mw-redirect" title="Foot pound force">foot pound force</a> (4.1550 <a href="/wiki/Joule" title="Joule">J</a>·<a href="/wiki/Calorie" title="Calorie">cal</a><sup>−1</sup>). Joule contended that <a href="/wiki/Motion_(physics)" class="mw-redirect" title="Motion (physics)">motion</a> and heat were mutually interchangeable and that, in every case, a given amount of work would generate the same amount of heat. Von Mayer also published a numerical value for mechanical equivalent of heat in 1845 but his experimental method wasn't as convincing. </p><p>Though a standardised value of 4.1860 J·cal<sup>−1</sup> was established in the early 20th century, in the 1920s, it was ultimately realised that the constant is simply the <a href="/wiki/Specific_heat" class="mw-redirect" title="Specific heat">specific heat</a> of water, a quantity that varies with temperature between the values of 4.17 and 4.22 J·<a href="/wiki/Gram" title="Gram">g</a><sup>−1</sup>·<a href="/wiki/Celsius" title="Celsius">°C</a><sup>−1</sup>. The change in unit was the result of the demise of the <a href="/wiki/Calorie#Chemistry" title="Calorie">calorie as a unit in physics and chemistry</a>. </p><p>Both von Mayer and Joule met with initial neglect and resistance despite having published in leading European physics journals, but by 1847, a lot of leading scientists of the day were paying attention. <a href="/wiki/Hermann_Helmholtz" class="mw-redirect" title="Hermann Helmholtz">Hermann Helmholtz</a> in 1847 published what is considered a definitive declaration of the <a href="/wiki/Conservation_of_energy" title="Conservation of energy">conservation of energy</a>. Helmholtz had learned from reading Joule's publications, though Helmholtz eventually came around to crediting both Joule and von Mayer for priority. </p><p>Also in 1847, Joule made a well-attended presentation at the annual meeting of <a href="/wiki/British_Association_for_the_Advancement_of_Science" class="mw-redirect" title="British Association for the Advancement of Science">British Association for the Advancement of Science</a>. Among those in attendance was <a href="/wiki/William_Thomson,_1st_Baron_Kelvin" class="mw-redirect" title="William Thomson, 1st Baron Kelvin">William Thomson</a>. Thomson was intrigued but initially skeptical. Over the next two years, Thomson became increasingly convinced of Joule's theory, finally admitting his conviction in print in 1851, simultaneously crediting von Mayer. Thomson collaborated with Joule, mainly by correspondence, Joule conducting experiments, Thomson analysing the results and suggesting further experiments. The collaboration lasted from 1852 to 1856. Its published results did much to bring about general acceptance of Joule's work and the <a href="/wiki/Kinetic_theory_of_gases" title="Kinetic theory of gases">kinetic theory</a>. </p><p>However, in 1848, von Mayer had first had sight of Joule's papers and wrote to the <a href="/wiki/France" title="France">French</a> <a href="/wiki/Acad%C3%A9mie_des_Sciences" class="mw-redirect" title="Académie des Sciences">Académie des Sciences</a> to assert priority. His letter was published in the <i><a href="/wiki/Comptes_Rendus" class="mw-redirect" title="Comptes Rendus">Comptes Rendus</a></i> and Joule was quick to react. Thomson's close relationship with Joule allowed him to become dragged into the controversy. The pair planned that Joule would admit von Mayer's priority for the idea of the mechanical equivalent but to claim that experimental verification rested with Joule. Thomson's associates, co-workers and relatives such as <a href="/wiki/William_John_Macquorn_Rankine" class="mw-redirect" title="William John Macquorn Rankine">William John Macquorn Rankine</a>, <a href="/wiki/James_Thomson_(engineer)" title="James Thomson (engineer)">James Thomson</a>, <a href="/wiki/James_Clerk_Maxwell" title="James Clerk Maxwell">James Clerk Maxwell</a>, and <a href="/wiki/Peter_Guthrie_Tait" title="Peter Guthrie Tait">Peter Guthrie Tait</a> joined to champion Joule's cause. </p><p>However, in 1862, <a href="/wiki/John_Tyndall" title="John Tyndall">John Tyndall</a>, in one of his many excursions into <a href="/wiki/Popular_science" title="Popular science">popular science</a> and many public disputes with Thomson and his circle, gave a lecture at the <a href="/wiki/Royal_Institution" title="Royal Institution">Royal Institution</a> entitled <i>On Force</i><sup class="plainlinks nourlexpansion citation" id="ref_unit1"><a class="external autonumber" href="https://en.wikipedia.org/wiki/Mechanical_equivalent_of_heat#endnote_unit1">[1]</a></sup> in which he credited von Mayer with conceiving and measuring the mechanical equivalent of heat. Thomson and Tait were angered, and an undignified public exchange of correspondence took place in the pages of the <i><a href="/wiki/Philosophical_Magazine" title="Philosophical Magazine">Philosophical Magazine</a></i>, and the rather more popular <i>Good Words</i>. Tait even resorted to championing <a href="/wiki/Ludwig_A._Colding" title="Ludwig A. Colding">Colding's</a> cause in an attempt to undermine von Mayer. </p><p>Though Tyndall again pressed von Mayer's cause in <i>Heat: A Mode of Motion</i> (1863) with the publication of Sir <a href="/wiki/Henry_Enfield_Roscoe" class="mw-redirect" title="Henry Enfield Roscoe">Henry Enfield Roscoe</a>'s <i><a href="/wiki/Edinburgh_Review" title="Edinburgh Review">Edinburgh Review</a></i> article <i>Thermo-Dynamics</i> in January 1864, Joule's reputation was sealed while that of von Mayer entered a period of obscurity. </p> <div class="mw-heading mw-heading2"><h2 id="Notes">Notes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mechanical_equivalent_of_heat&action=edit&section=2" title="Edit section: Notes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ol><li><style data-mw-deduplicate="TemplateStyles:r1041539562">.mw-parser-output .citation{word-wrap:break-word}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}</style><span class="citation wikicite" id="endnote_unit1"><b><a href="#ref_unit1">^</a></b></span> The usage of terms such as <i>work</i>, <i>force</i>, <i>energy</i>, <i>power</i>, <i>etc.</i> in the 18th and 19th centuries by scientific workers does not necessarily reflect the standardised modern usage.</li></ol> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mechanical_equivalent_of_heat&action=edit&section=3" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text">Lervig, P. Sadi Carnot and the steam engine:Nicolas Clément's lectures on industrial chemistry, 1823-28. Br. J Hist. Sci. 18::147, 1985.</span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mechanical_equivalent_of_heat&action=edit&section=4" title="Edit section: Further reading"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/L%C3%A9on_Foucault" title="Léon Foucault">Foucault, L.</a> (1854) “Equivalent mécanique de la chaleur. M. Mayer, M. Joule. Chaleur spécifique des gaz sous volume constant. M. Victor Regnault”, <i>Journal des débats politiques et littéraires</i>, Thursday 8 June</li> <li><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFLloyd,_J.T.1970" class="citation journal cs1">Lloyd, J.T. (1970). "Background to the Joule-Mayer Controversy". <i>Notes and Records of the Royal Society</i>. <b>25</b> (2): 211–225. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1098%2Frsnr.1970.0030">10.1098/rsnr.1970.0030</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:71802199">71802199</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Notes+and+Records+of+the+Royal+Society&rft.atitle=Background+to+the+Joule-Mayer+Controversy&rft.volume=25&rft.issue=2&rft.pages=211-225&rft.date=1970&rft_id=info%3Adoi%2F10.1098%2Frsnr.1970.0030&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A71802199%23id-name%3DS2CID&rft.au=Lloyd%2C+J.T.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMechanical+equivalent+of+heat" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSharlin,_H.I.1979" class="citation book cs1">Sharlin, H.I. (1979). <i>Lord Kelvin: The Dynamic Victorian</i>. Pennsylvania State University Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-271-00203-4" title="Special:BookSources/0-271-00203-4"><bdi>0-271-00203-4</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Lord+Kelvin%3A+The+Dynamic+Victorian&rft.pub=Pennsylvania+State+University+Press&rft.date=1979&rft.isbn=0-271-00203-4&rft.au=Sharlin%2C+H.I.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMechanical+equivalent+of+heat" class="Z3988"></span>, <i>pp</i>. 154–5</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSmith,_C.1998" class="citation book cs1">Smith, C. (1998). <i>The Science of Energy: A Cultural History of Energy Physics in Victorian Britain</i>. Chicago University Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-226-76421-4" title="Special:BookSources/0-226-76421-4"><bdi>0-226-76421-4</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Science+of+Energy%3A+A+Cultural+History+of+Energy+Physics+in+Victorian+Britain&rft.pub=Chicago+University+Press&rft.date=1998&rft.isbn=0-226-76421-4&rft.au=Smith%2C+C.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMechanical+equivalent+of+heat" class="Z3988"></span></li> <li>Smith, C. (2004) "Joule, James Prescott (1818-1889)", <i><a href="/wiki/Oxford_Dictionary_of_National_Biography" class="mw-redirect" title="Oxford Dictionary of National Biography">Oxford Dictionary of National Biography</a></i>, Oxford University Press, <<a rel="nofollow" class="external free" href="http://www.oxforddnb.com/view/article/15139">http://www.oxforddnb.com/view/article/15139</a>, accessed 27 July 2005> (subscription required)</li> <li>Zemansky, M.W. (1968) <i>Heat and Thermodynamics: An Intermediate Textbook</i>, McGraw-Hill, <i>pp</i>. 86–87</li></ul> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mechanical_equivalent_of_heat&action=edit&section=5" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Commons-logo.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/12px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/24px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></a></span> 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href="/wiki/History_of_special_relativity" title="History of special relativity">Special relativity</a> <ul><li><a href="/wiki/Timeline_of_special_relativity_and_the_speed_of_light" title="Timeline of special relativity and the speed of light">timeline</a></li> <li><a href="/wiki/History_of_Lorentz_transformations" title="History of Lorentz transformations">Lorentz transformations</a></li> <li><a href="/wiki/Tests_of_special_relativity" title="Tests of special relativity">tests</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Recent developments</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li>Quantum information <ul><li><a href="/wiki/Timeline_of_quantum_computing_and_communication" title="Timeline of quantum computing and communication">timeline</a></li></ul></li> <li><a href="/wiki/History_of_loop_quantum_gravity" title="History of loop quantum gravity">Loop quantum gravity</a></li> <li><a href="/wiki/History_of_nanotechnology" title="History of nanotechnology">Nanotechnology</a></li> <li><a href="/wiki/History_of_string_theory" title="History of string theory">String theory</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">On specific discoveries</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Discovery_of_cosmic_microwave_background_radiation" title="Discovery of cosmic microwave background radiation">Cosmic microwave background</a></li> <li><a href="/wiki/Discovery_of_graphene" title="Discovery of graphene">Graphene</a></li> <li><a href="/wiki/First_observation_of_gravitational_waves" title="First observation of gravitational waves">Gravitational waves</a></li> <li>Subatomic particles <ul><li><a href="/wiki/Timeline_of_particle_discoveries" title="Timeline of particle discoveries">timeline</a></li> <li><a href="/wiki/Search_for_the_Higgs_boson" title="Search for the Higgs boson">Higgs boson</a></li> <li><a href="/wiki/Discovery_of_the_neutron" title="Discovery of the neutron">Neutron</a></li></ul></li> <li><a href="/wiki/R%C3%B8mer%27s_determination_of_the_speed_of_light" title="Rømer's determination of the speed of light">Speed of light</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">By periods</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Copernican_Revolution" title="Copernican Revolution">Copernican Revolution</a></li> <li><a href="/wiki/Golden_age_of_physics" title="Golden age of physics">Golden age of physics</a></li> <li><a href="/wiki/Golden_age_of_cosmology" title="Golden age of cosmology">Golden age of cosmology</a></li> <li><a href="/wiki/Physics_in_the_medieval_Islamic_world" title="Physics in the medieval Islamic world">Medieval Islamic world</a> <ul><li><a href="/wiki/Astronomy_in_the_medieval_Islamic_world" title="Astronomy in the medieval Islamic world">Astronomy</a></li></ul></li> <li><a href="/wiki/Noisy_intermediate-scale_quantum_era" title="Noisy intermediate-scale quantum era">Noisy intermediate-scale quantum era</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">By groups</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Harvard_Computers" title="Harvard Computers">Harvard Computers</a></li> <li><a href="/wiki/The_Martians_(scientists)" title="The Martians (scientists)">The Martians</a></li> <li><a href="/wiki/Oxford_Calculators" title="Oxford Calculators">Oxford Calculators</a></li> <li><a href="/wiki/Via_Panisperna_boys" title="Via Panisperna boys">Via Panisperna boys</a></li> <li><a href="/wiki/Women_in_physics" title="Women in physics">Women in physics</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Scientific disputes</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Bohr%E2%80%93Einstein_debates" title="Bohr–Einstein debates">Bohr–Einstein</a></li> <li><a href="/wiki/Chandrasekhar%E2%80%93Eddington_dispute" title="Chandrasekhar–Eddington dispute">Chandrasekhar–Eddington</a></li> <li><a href="/wiki/Galileo_affair" title="Galileo affair">Galileo affair</a></li> <li><a href="/wiki/Leibniz%E2%80%93Newton_calculus_controversy" title="Leibniz–Newton calculus controversy">Leibniz–Newton</a></li> <li><a class="mw-selflink selflink">Joule–von Mayer</a></li> <li><a href="/wiki/Great_Debate_(astronomy)" title="Great Debate (astronomy)">Shapley–Curtis</a></li> <li>Relativity priority <ul><li><a href="/wiki/Relativity_priority_dispute" title="Relativity priority dispute">Special relativity</a></li> <li><a href="/wiki/General_relativity_priority_dispute" title="General relativity priority dispute">General relativity</a></li></ul></li> <li><a href="/wiki/Transfermium_Wars" title="Transfermium Wars">Transfermium Wars</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:History_of_physics" title="Category:History of physics">Category</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="History_of_chemistry_(timeline)" style="padding:3px"><table class="nowraplinks hlist mw-collapsible mw-collapsed navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:History_of_chemistry" title="Template:History of chemistry"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/w/index.php?title=Template_talk:History_of_chemistry&action=edit&redlink=1" class="new" title="Template talk:History of chemistry (page does not exist)"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:History_of_chemistry" title="Special:EditPage/Template:History of chemistry"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="History_of_chemistry_(timeline)" style="font-size:114%;margin:0 4em"><a href="/wiki/History_of_chemistry" title="History of chemistry">History of chemistry</a> (<a href="/wiki/Timeline_of_chemistry" title="Timeline of chemistry">timeline</a>)</div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">By branch</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Physical chemistry (<a href="/wiki/Timeline_of_physical_chemistry" title="Timeline of physical chemistry">timeline</a>)</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/History_of_atomic_theory" title="History of atomic theory">Atomic theory</a></li> <li><a href="/wiki/History_of_molecular_theory" title="History of molecular theory">Molecular theory</a></li> <li><a href="/wiki/History_of_electrochemistry" title="History of electrochemistry">Electrochemistry</a></li> <li><a href="/wiki/History_of_spectroscopy" title="History of spectroscopy">Spectroscopy</a></li> <li><a href="/wiki/History_of_thermodynamics" title="History of thermodynamics">Thermodynamics</a> <ul><li><a href="/wiki/Timeline_of_thermodynamics" title="Timeline of thermodynamics">timeline</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Organic chemistry (<a href="/wiki/Timeline_of_biology_and_organic_chemistry" title="Timeline of biology and organic chemistry">timeline</a>)</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/History_of_biochemistry" title="History of biochemistry">Biochemistry</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Nuclear chemistry</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Discovery_of_nuclear_fission" title="Discovery of nuclear fission">Fission</a></li> <li><a href="/wiki/History_of_nuclear_fusion" title="History of nuclear fusion">Fusion</a></li> <li><a href="/wiki/History_of_nuclear_power" title="History of nuclear power">Power</a></li> <li><a href="/wiki/History_of_nuclear_weapons" title="History of nuclear weapons">Weapons</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Applied chemistry</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/History_of_cosmetics" title="History of cosmetics">Cosmetics</a></li> <li><a href="/wiki/History_of_materials_science" title="History of materials science">Material science</a></li> <li><a href="/wiki/History_of_nanotechnology" title="History of nanotechnology">Nanotechnology</a></li> <li><a href="/wiki/History_of_pharmacy" title="History of pharmacy">Pharmacy</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Ancient history</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chinese_alchemy" title="Chinese alchemy">Chinese alchemy</a></li> <li><a href="/wiki/Alchemy_in_the_medieval_Islamic_world" title="Alchemy in the medieval Islamic world">Medieval Islamic World alchemy</a></li> <li><a href="/wiki/History_of_metallurgy_in_the_Indian_subcontinent" title="History of metallurgy in the Indian subcontinent">Indian metallurgy</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/History_of_the_periodic_table" title="History of the periodic table">Periodic table</a> (<a href="/wiki/Discovery_of_chemical_elements" title="Discovery of chemical elements">timeline</a>)</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th id="By_elements" scope="row" class="navbox-group" style="width:1%">By elements</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/History_of_fluorine" title="History of fluorine">F</a></li> <li><a href="/wiki/History_of_aluminium" title="History of aluminium">Al</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">On specific discoveries</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/History_of_the_battery" title="History of the battery">Battery</a></li> <li>Carbon nanotubes <ul><li><a href="/wiki/Timeline_of_carbon_nanotubes" title="Timeline of carbon nanotubes">timeline</a></li></ul></li> <li><a href="/wiki/History_of_electrophoresis" title="History of electrophoresis">Electrophoresis</a></li> <li><a href="/wiki/History_of_manufactured_fuel_gases" title="History of manufactured fuel gases">Gaseous fuel</a></li> <li><a href="/wiki/Discovery_of_graphene" title="Discovery of graphene">Graphene</a></li> <li><a href="/wiki/History_of_gunpowder" title="History of gunpowder">Gunpowder</a></li> <li><a href="/wiki/History_of_the_Haber_process" title="History of the Haber process">Haber process</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Scientific disputes</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/List_of_chemical_element_naming_controversies" title="List of chemical element naming controversies">Element naming</a></li> <li><a class="mw-selflink selflink">Joule–von Mayer</a></li> <li><a href="/wiki/Transfermium_Wars" title="Transfermium Wars">Transfermium Wars</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Women_in_chemistry" title="Women in chemistry">Women in chemistry</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" 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