Charles Blagden

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Charles Blagden

Sir Charles Brian Blagden (born April 17, 1748 in Wotton-Under-Edge , Gloucestershire , † March 26, 1820 in Arcueil ) was a British doctor and naturalist .

Life

The parents of Charles Blagden and his siblings John (1740-1808, since 1784: John Blagden Hale), Thomas (1742-1815), Mary (* 1745) and Richard (* 1749) were John Blagden (1715-1750) and his Wife Elizabeth Phelps. Charles Blagden studied medicine in Edinburgh from 1765 to 1768 . In 1768 he received his doctorate in medicine under William Robertson with a thesis De causis apoplexiae (On the causes of stroke ). He attended lectures by the physicist and chemist Joseph Black and the physician and chemist William Cullen , with whom he was friends. After completing his studies, he first practiced in Gloucester Hospital , but went to London in 1772, where he was elected Fellow of the Royal Society on June 25th . There he joined the British Army as a military doctor. During the American War of Independence (1775–1783) he was stationed first on the hospital ship HMS Pigot and later in the British colonies in North America. In 1779 General Cornwallis gave him permission to return to England. From 1780 he lived in Plymouth and worked in a military hospital . At the beginning of 1783 he retired from active service with half pay .

Blagden felt isolated from scientific life in Plymouth and therefore moved to the British capital in 1782. Here he first lived with his brother John Blagden Hale and continued to practice as a doctor. In 1789 he was elected to the American Academy of Arts and Sciences . In London he was close friends with Henry Cavendish , with whom he researched together until around 1790. Cavendish also supported Blagden financially, leaving him a legacy of £ 15,000 on his death in 1810 , around £ 1,140,000 in today's value. Furthermore, Blagden was in long-term exchange with the President of the Royal Society, Sir Joseph Banks , on whose proposal Blagden was elected on May 5, 1784 as one of the two secretaries of the Royal Society. He also frequented the so-called Monday Club , which met in the George & Vulture coffee house .

From June to August 1783 Blagden was in Paris for the first time and witnessed experiments by Antoine Lavoisier and Pierre-Simon Laplace . He also met the Marquis de Condorcet , Bochart de Saron (1730–1794), Cassini de Thury and his son, Count Cassini . In 1789, Blagden was elected a corresponding member of the Académie des Sciences and a member of the American Philosophical Society . In 1788 he received the Copley Medal of the Royal Society, and in 1792 he was raised to the nobility as a Knight Bachelor . Since 1807 he was a corresponding member of the Bavarian Academy of Sciences .

On November 30, 1797, Blagden resigned as Secretary of the Royal Society because of his deteriorating eyesight. After the peace treaty between England and France in 1814, he spent half of the year in the last years of his life on the continent, especially in France, where he had many friends among French scientists and naturalists, such as Claude-Louis Berthollet and other members of the Société d ' Arcueil . From July 1807 he was named in the Mémoires de Physique et de Chimie de la Société d'Arcueil as a member of the Société . During one of these stays Blagden died in the house of his friend Berthollet in Arcueil.

Scientific achievements

His experiments on the effect of dissolved substances on the freezing point of water led to the Blagden's law ( lowering of the freezing point ), named after him , which says that salt lowers the freezing point of water. It does this in a simple inverse proportion to the amount of water.

Blagden also experimented with the human temperature regulation ability. In his 1775 report to the Royal Society, he recognized the role of sweating in thermoregulation . On January 23, 1774, Blagden carried out a self-experiment in a heating chamber with George Fordyce , Joseph Banks and six other men . The heating chamber actually consisted of three chambers, each with a different temperature optimum. The hottest chamber, with a dome-shaped roof, was heated via hot air ducts in the floor and, if necessary, with additional hot infusions or the humidity was changed. The aim of the experiment was to find out what outside temperature the human body can endure. They started at 45 ° Celsius and gradually increased to approx. 100 ° Celcius and later to 127 ° Celcius. First, the experiment was carried out fully clothed for eight minutes, in street clothes with gloves and stockings, and later partly naked. A dog was also taken along at times. At the same time, a piece of meat was placed on a tin frame. After about three quarters of an hour, the participants were exhausted, dehydrated, and bathed in sweat. In contrast, the steak was almost completely cooked. Blagden attributed the difference between the "live meat" and the beef steak to heat adaptation. Thus Blagden described the effects of different types of heat on the body functions (e.g. sweating, heart rate). He also examined the essential function of evaporative cooling and the different effects of dry and moist heat.

Fonts (selection)

  • Tentamen medicum inaugurale de causis apoplexiae . Edinburgh 1768. Dissertation.
  • Experiments and Observations in an Heated Room . In: Philosophical Transactions . Volume 65, 1775, pp. 111-123, doi: 10.1098 / rstl.1775.0013 .
  • Further Experiments and Observations in an Heated Room . In: Philosophical Transactions . Volume 65, 1775, pp. 484-494, doi: 10.1098 / rstl.1775.0048 .
  • On the Heat of the Water in the Gulf Stream . In: Philosophical Transactions . Volume 71, 1781, pp. 334-344, doi: 10.1098 / rstl.1781.0042 .
  • With Edward Nairne : Proceedings Relative to the Accident by Lightning at Heckingham . In: Philosophical Transactions . Volume 72, 1782, pp. 355-378, doi: 10.1098 / rstl.1782.0024 .
  • History of the Congelation of Quicksilver . In: Philosophical Transactions . Volume 73, 1783, pp. 329-397, doi: 10.1098 / rstl.1783.0022 .
  • An Account of Some Late Fiery Meteors; With observations . In: Philosophical Transactions . Volume 74, 1784, pp. 201-232, doi: 10.1098 / rstl.1784.0019
  • Some Observations on Ancient Inks, with the Proposal of a New Method of Recovering the Legibility of Decayed Writings . In: Philosophical Transactions . Volume 77, 1787 pp. 451-457, doi: 10.1098 / rstl.1787.0039 .
  • Experiments on the Cooling of Water below Its Freezing Point . In: Philosophical Transactions . Volume 78, 1788, pp. 125-146, doi: 10.1098 / rstl.1788.0011 .
  • Sur le Refroidissement de l'eau au-dessous du terme de la Congelation. (Extrait de la premiere partie des Transactions Philosophiques by M. Adet) . In: Annales de Chimie . Volume 4, 1790, pp. 229-248 (online) .
  • Report on the Best Method of Proportioning the Excise upon Spirituous Liquors . In: Philosophical Transactions . Volume 80, 1790, pp. 321-345, doi: 10.1098 / rstl.1790.0022 .
  • Report on the meilleure méthode de proportionner les droits sur les liqueurs spiritueuses . In: Annales de Chimie . Volume 15, 1792, pp. 37-82 (online) .
  • Some Account of the Tides at Naples . In: Philosophical Transactions . Volume 83, 1793, p. 168, doi: 10.1098 / rstl.1793.0016 .
  • Sur les parties constituantes du tannin . In: Annales de Chimie . Vol. 55, 1805, pp. 84-86 (online) .
  • An Appendix to Mr. Ware's Paper on Vision . In: Philosophical Transactions . Volume 103, 1813, pp. 110-113, doi: 10.1098 / rstl.1813.0017 .
  • The laws of overcooling and lowering of the freezing point (1788). Published by AJ von Oettingen. Ostwalds Klassiker 56, Leipzig 1894, archive

literature

  • Clara Anderson: Blagden Papers at the Royal Society. In: Notes and Records of the Royal Society. Volume 61, 2007, pp. 237-238, doi: 10.1098 / rsnr.2007.0177 .
  • Charles Blagden: Letters from Sir Charles Blagden to Sir Joseph Banks on American Natural History and Politics, 1776–1786. In: Bulletin of the New York Public Library . Volume 7, 1903.
  • Danielle ME Fauque: An Englishman abroad: Charles Blagden's visit to Paris in 1783. In: Notes and Records of the Royal Society. Volume 62, 2008, pp. 373-390, doi: 10.1098 / rsnr.2008.0041 .
  • Frederick Hutton Getman: Sir Charles Blagden, FRS . In: Osiris . Volume 3, 1937, pp. 69-87, (JSTOR) .
  • B. Hill: In war and peace Sir Charles Blagden, MDEd., FRS (1748-1820). In: The Practitioner. Volume 217, Number 1297, July 1976, pp. 126-131, ISSN  0032-6518 . PMID 792860 .

Web links

Wikisource: Charles Blagden  - Sources and full texts

Individual evidence

  1. ↑ David Hale, Joan Hale: Hale Families Of Wiltshire. In: hale-genealogy.com. August 16, 2009, accessed on March 26, 2020 (English, genealogical representation).
  2. ↑ David Hale, Joan Hale: The Blagden Family of Alderley, Gloucestershire. In: hale-genealogy.com. August 16, 2009, accessed on March 26, 2020 (English, genealogical representation).
  3. ↑ Christa Jungnickel, Russell McCormmach: Cavendish. The Experimental Life. Bucknell, Pennsylvania 1999, p. 291 .
  4. ^ Clara Anderson: Blagden Papers at the Royal Society. In: Notes and Records of the Royal Society . Volume 61, pp. 237-238 doi: 10.1098 / rsnr.2007.0177 .
  5. ↑ a b Christa Jungnickel, Russell McCormmach: Cavendish. The Experimental Life. Bucknell, Pennsylvania 1999, p. 293 .
  6. ↑ Christa Jungnickel, Russell McCormmach: Cavendish. The Experimental Life. Bucknell, Pennsylvania 1999, pp. 464-467, 502-504.
  7. ^ Banks, Joseph: The Scientific Correspondence of Sir Joseph Banks, 1765-1820.
  8. ↑ Christa Jungnickel, Russell McCormmach: Cavendish. The Experimental Life. Bucknell, Pennsylvania 1999, pp. 346-347.
  9. ^ Bryant Lillywhite: London Coffee Houses; a Reference Book of Coffee Houses of the Seventeenth, Eighteenth and Nineteenth Centuries. 1963.
  10. ^ Member History: Charles Blagden. American Philosophical Society, accessed May 4, 2018 .
  11. ↑ John Nichols: The Gentleman's magazine and historical chronicle. Volume 64, S. Urban, p. 1115.
  12. ↑ member entry by Sir Charles Blagden at the Bavarian Academy of Sciences , accessed on January 2 2017th
  13. ↑ Christa Jungnickel, Russell McCormmach: Cavendish. The Experimental Life. Bucknell, Pennsylvania 1999, p. 466.
  14. ^ Joseph William Mellor: Modern inorganic chemistry. Longmans, Green & Company. New York 1912, p. 161.
  15. ↑ Charles Blagden: Experiments and Observations in a Heated Room . In: Philosophical Transactions . Volume 65, 1775, pp. 111-123, doi: 10.1098 / rstl.1775.0013 .
personal data
SURNAME Blagden, Charles
ALTERNATIVE NAMES Blagden, Charles Brian
BRIEF DESCRIPTION British physician and naturalist
DATE OF BIRTH April 17, 1748
PLACE OF BIRTH Wotton-Under-Edge , Gloucestershire
DATE OF DEATH March 26, 1820
Place of death Arcueil