Editing Specific heat capacity (section)

=== Discovery of specific heat ===
[[File:Black Joseph (cropped).jpg|thumb|196x196px|Joseph Black]]
One of the first scientists to use the concept was [[Joseph Black]], an 18th-century medical doctor and professor of medicine at [[Glasgow University]]. He measured the specific heat capacities of many substances, using the term ''capacity for heat''.<ref>
{{cite book |last1=Laidler |first1=Keith J. |url=https://books.google.com/books?id=01LRlPbH80cC |title=The World of Physical Chemistry |publisher=Oxford University Press |year=1993 |isbn=0-19-855919-4}}</ref> In 1756 or soon thereafter, Black began an extensive study of heat.<ref name=":1">{{Cite book |last=Ramsay |first=William |author-link=William Ramsay |title=The life and letters of Joseph Black, M.D. |publisher=Constable |year=1918 |pages=38–39}}</ref> In 1760 he realized that when two different substances of equal mass but different temperatures are mixed, the changes in number of degrees in the two substances differ, though the heat gained by the cooler substance and lost by the hotter is the same. Black related an experiment conducted by [[Daniel Gabriel Fahrenheit]] on behalf of Dutch physician [[Herman Boerhaave]]. For clarity, he then described a hypothetical, but realistic variant of the experiment: If equal masses of 100&nbsp;°F water and 150&nbsp;°F mercury are mixed, the water temperature increases by 20&nbsp;° and the mercury temperature decreases by 30&nbsp;° (both arriving at 120&nbsp;°F), even though the heat gained by the water and lost by the mercury is the same. This clarified the distinction between heat and temperature. It also introduced the concept of specific heat capacity, being different for different substances. Black wrote: “Quicksilver [mercury] ... has less capacity for the matter of heat than water.”<ref>{{Cite book |last=Black |first=Joseph |url=https://books.google.com/books?id=lqI9AQAAMAAJ&pg=PA76 |title=Lectures on the Elements of Chemistry: Delivered in the University of Edinburgh |date=1807 |publisher=Mathew Carey |editor-last=Robison |editor-first=John |edition= |volume=1 |pages=76–77 |language=en}}</ref><ref name=":0">{{Cite journal |last=West |first=John B. |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>