Editing Benjamin Thompson (section)

===Calorific and frigorific radiation===
He explained [[Marc-Auguste Pictet|Pictet's experiment]], which demonstrates the reflection of cold, by supposing that all bodies emit invisible rays, undulations in the ethereal fluid.<ref>{{cite web
 | title = Pictet's experiment: The apparent radiation and reflection of cold
 | author = James Evans and Brian Popp
 | publisher = Am. J. Phys. 53 (8)
 | year = 1985
 | pages = 737–753
 | url = http://www2.ups.edu/faculty/jcevans/Pictet's%20experiment.pdf
 }}</ref> He did experiments to support his theories of calorific and frigorific radiation and said the communication of heat was the net effect of calorific (hot) rays and frigorific (cold) rays and the rays emitted by the object. When an object absorbs radiation from a warmer object (calorific rays) its temperature rises, and when it absorbs radiation from a colder object (frigorific rays) its temperature falls. See note 8, "An enquiry concerning the nature of heat and the mode of its communication" Philosophical Transactions of the Royal Society, starting at page 112.{{Full citation needed|date=May 2020}}