Sir Charles Brian Blagden FRS (17 April 1748 – 26 March 1820)[1] was an English physician and chemist.

[4] In 1780, he returned to a medical post in Plymouth but in late 1782 or early 1783 left for London to become an assistant and amanuensis to Henry Cavendish.

[5] Lavoisier's dissatisfaction with the Cavendish's "dephlogistinization" theory led him to the concept of a chemical reaction, which he reported to the Royal Academy on 24 June 1783, effectively founding modern chemistry.

[8] In his report to the Royal Society in 1775, he was first Western scientist to officially recognise the role of perspiration in thermoregulation.

[8][9] Blagden's experiments on how dissolved substances like salt affected the freezing point of water led to the discovery that the freezing point of a solution decreases in direct proportion to the concentration of the solution, now called Blagden's Law.