Editing Calorie (section)

==History==

The term "calorie" comes {{ety|la|calor|heat}}.<ref name="MW_calorie">{{cite encyclopedia |title="Calorie." |encyclopedia=Merriam-Webster.com Dictionary |url=https://www.merriam-webster.com/dictionary/calorie |access-date=2024-03-20 }}</ref> It was first introduced by [[Nicolas Clément]], as a unit of [[heat]] energy, in lectures on experimental [[calorimetry]] during the years 1819–1824. This was the "large" calorie.<ref name=marsh2020/><ref name=harg2007/><ref name=harg2006/> The term (written with lowercase "c") entered French and English dictionaries between 1841 and 1867.

The same term was used for the "small" unit by [[Pierre Antoine Favre]] (chemist) and Johann T. Silbermann (physicist) in 1852.

In 1879, [[Marcellin Berthelot]] distinguished between gram-calorie and kilogram-calorie, and proposed using "Calorie", with capital "C", for the large unit.<ref name=marsh2020/> This usage was adopted by [[Wilbur Olin Atwater]], a professor at [[Wesleyan University]], in 1887, in an influential article on the energy content of food.<ref name=marsh2020/><ref name=harg2007/>

The smaller unit was used by U.S. physician [[Joseph Howard Raymond]], in his classic 1894 textbook ''A Manual of Human Physiology''.<ref name=raym1894/> He proposed calling the "large" unit "kilocalorie", but the term did not catch on until some years later.

The small calorie (cal) was recognized as a unit of the [[CGS system]] in 1896,<ref name=marsh2020/><ref name=harg2006/> alongside the already-existing CGS unit of energy, the [[erg]] (first suggested by Clausius in 1864, under the name ''ergon'', and officially adopted in 1882).

In 1928, there were already serious complaints about the possible confusion arising from the two main definitions of the calorie and whether the notion of using the capital letter to distinguish them was sound.<ref name=marks1928/>

The joule was the officially adopted SI unit of energy at the ninth [[General Conference on Weights and Measures]] in 1948.<ref name=CIPM1948/><ref name=BIPM9th/> The calorie was mentioned in the 7th edition of the SI brochure as an example of a non-SI unit.<ref name=BIPM7th/>

The alternate spelling {{linktext|calory}} is a less-common, non-standard variant.<ref name="MW_calorie" />