Sir Charles Brian Blagden FRS (17 April 1748 – 26 March 1820) was an English physician and chemist. He served as a medical officer in the Army (1776–1780) and later held the position of Secretary of the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

(1784–1797). Blagden won the Copley Medal in 1788 and was knighted in 1792. He died in

Arcueil Arcueil () is a commune in the Val-de-Marne department in the southern suburbs of Paris, France. It is located from the center of Paris. Name The name Arcueil was recorded for the first time in 1119 as ''Arcoloï'', and later in the 12th ...

, France in 1820, and was buried at Père Lachaise Cemetery in Paris.

Science

Royal Society - Charles Blagden collection 4

In June 1783, Blagden, then assistant to

Henry Cavendish Henry Cavendish ( ; 10 October 1731 – 24 February 1810) was an English natural philosopher and scientist who was an important experimental and theoretical chemist and physicist. He is noted for his discovery of hydrogen, which he termed "infl ...

, visited

Antoine Lavoisier Antoine-Laurent de Lavoisier ( , ; ; 26 August 17438 May 1794),
CNRS (

chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...

, which he reported to the Royal Academy of Sciences on 24 June 1783, effectively founding modern chemistry. He was elected a Foreign Honorary Member of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

in 1789. He was elected to the

American Philosophical Society The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...

in 1789. Blagden experimented on human ability to withstand high temperatures. In 1775 he showed that human beings could withstand room temperatures as high as 260 degrees Fahrenheit (127 degrees Celsius).. In his report to the Royal Society in 1775, he was first Western scientist to officially recognise the role of

perspiration Perspiration, also known as sweating, is the production of fluids secreted by the sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distr ...

thermoregulation Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...

. Blagden's experiments on how dissolved substances like salt affected the freezing point of water led to the discovery that ''the

freezing point The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depend ...

of a

solution Solution may refer to: * Solution (chemistry), a mixture where one substance is dissolved in another * Solution (equation), in mathematics ** Numerical solution, in numerical analysis, approximate solutions within specified error bounds * Soluti ...

decreases in direct proportion to the

concentration In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: '' mass concentration'', ''molar concentration'', '' number concentration'', ...

of the solution'', now called Blagden's Law.

References

External links

Blagden Papers at the Royal Society

National Public Radio
story about Blagden's experiment in a hot room * Sir Charles Blagden Papers. James Marshall and Marie-Louise Osborn Collection, Beinecke Rare Book and Manuscript Library, Yale University. {{DEFAULTSORT:Blagden, Charles 1748 births 1820 deaths Fellows of the Royal Society Recipients of the Copley Medal 19th-century English medical doctors 18th-century English medical doctors 19th-century English chemists 18th-century English chemists Fellows of the American Academy of Arts and Sciences People from Wotton-under-Edge Burials at Père Lachaise Cemetery

Science

References

Further reading

External links