Josef Loschmidt

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Josef Loschmidt
Josef Loschmidt's grave in Vienna's central cemetery

Johann Josef Loschmidt (Czech also: Jan Josef Loschmidt) (born March 15, 1821 in Putschirn , Bohemia ; † July 8, 1895 in Vienna ) was a Bohemian-Austrian physicist and chemist .

Life

Josef Loschmidt (he only used his middle name all his life and is only known in literature as Josef or Joseph Loschmidt) was born as a child of poor small farmers in Putschirn near Karlsbad : his father Anton Lochschmidt lived in the small farm no.10 in Putschirn and earned a living his livelihood as a tailor and by farming, the mother Maria Anna, geb. Peterl was a cottage's daughter. On the advice of the priest Adalbert Czech, he received an education which, after finishing school at the Piarist monastery in Schlackenwerth (1833 to 1837), took him to Prague , where he went to the German-speaking university in 1839 . Here he came into contact with Franz Serafin Exner , professor of philosophy in Prague. At Exner's suggestion, Loschmidt tried to apply mathematical models to psychological questions. Although this project failed, it made Loschmidt a good mathematician. In 1841 he went to Vienna, where he graduated from the Polytechnic Institute in physics and chemistry in 1846 . After he was unable to find a scientific position, he first worked in a steel factory before founding a company in Vienna to manufacture potassium nitrate . This company went bankrupt, whereupon he worked as a teacher at a Vienna secondary school from 1856. In 1866 he got a job at the University of Vienna, where he already became an assistant professor in 1868 before he was professor of physical chemistry from 1872 to 1891 . He was also a teacher of Ludwig Boltzmann .

At the age of 66, Loschmidt married his longtime partner and housekeeper Karoline Mayr (1846–1930). A short time later, in 1887, Loschmidt's "(our) only child" (gravestone inscription) Josef was born, who died after his father in 1898, albeit in childhood. The honorary grave of the family is located in the Vienna Central Cemetery (56B-2-23). The fourth person who died last appears on the tombstone as a "Karoline Mayr (1885–1950), who was born 2 years before the son.

In 1953, Loschmidtgasse in Vienna's Floridsdorf (21st district) was named after him. A street in Berlin-Charlottenburg was named after him. In 2010 the large lecture hall II of the Chemical Institute of the University of Vienna was renamed the Joseph Loschmidt lecture hall.

Services

He did research in the fields of thermodynamics , electrodynamics and optics and on crystal forms. In 1861 he made proposals for the constitution of benzene as a ring-shaped structure for the first time .

In 1865 he determined the size of air molecules for the first time - on the basis of gas kinetics. At the same time, he was able to calculate the Loschmidt constant, later named after him, for the first time , which can be converted to the Avogadro constant that is used today .

In his work “Chemical Studies. Constitutional formulas of organic chemistry in graphic representation ”(published in 1861), Loschmidt described 368 (of which 121 aromatic) molecules with the help of his“ constitutional formulas ”, these are still very easy to understand for chemists and show the spatial orientation of the atoms. His formulas show double and triple bonds with a corresponding number of bars, as is still common today. Also included are formulas for ozone and that - only 21 years later officially from August Freund discovered - cyclopropane . Loschmidt wrote that phenyl rings presumably have similar constitutions as cyclopropane, so he probably knew about the ring-like appearance of benzene. August Kekulé knew Loschmidt's “constitutional formulas” before he published his version of the structure of the benzene ring, so some historians believe that Kekulé at least got his inspiration for the structure of benzene from Loschmidt's work.

Scheme of "benzoyl hydrogen" ( benzaldehyde ) from Loschmidts Chemischen Studien (1861)

Honors

  • In 1995 the Austrian postal administration issued a special postage stamp with a face value of ATS 20 on the occasion of the 100th anniversary of Josef Loschmidt's death .
  • Memorial plaque made of light stone with bust in a round arch, text, at the University of Vienna.
  • Memorial plaque on the house where he was born in Pocerny 10 (Putschirn).
  • Bronze plaque (designed by Prof. Ferdinand Welz) with a portrait at Haus Wien, Lacknergasse 79, his last home (1890–1895).
  • Portrait and memorial plaque (bronze, created by Mikos Armulidis, Ostrov) at the former Piarist monastery in Ostrov nad Ohří (German: Schlackenwerth), where he went to school (1833–1837). Unveiled October 4, 2003.
  • Gravestone at the grave of honor in Vienna.

Works

  • 1861: Chemical studies, constitution formulas of organic chemistry in graphic representation . Loschmidt financed the publication of the book himself, as he was not very well known at the time. The most important chapters of this work were later reissued by Richard Anschütz due to their importance.
  • 1865: On the size of the air molecules

literature

Individual evidence

  1. ↑ Ceremony and lecture hall renaming at the Faculty of Chemistry , archive of the online newspaper of the University of Vienna on October 28, 2010, accessed on March 14, 2014
  2. ↑ a b Josef Loschmidt: “On the size of the air molecules” in the reports of the meetings of the Imperial Academy of Sciences in Vienna , 52, Dept. II, pp. 395–413 (1866), online in the Google book search
  3. ↑ Special post stamp “100. Anniversary of the death of Josef Loschmidt ” . Austria Forum , accessed on March 20, 2017
  4. ↑ Loschweb> Proceedings
  5. ↑ Odhalení pamětní desky Josefu Loschmidtovi. (PDF) Retrieved December 16, 2017 (Czech, size: 319 KB).
  6. ^ Jan Josef Loschmidt (1821–1895) Loschmidt Laboratories> "Loschweb", accessed March 20, 2017.

Web links

personal data
SURNAME Loschmidt, Josef
ALTERNATIVE NAMES Loschmidt, Johann Josef (full name); Loschmidt, Joseph
BRIEF DESCRIPTION Austrian physicist and chemist
DATE OF BIRTH March 15, 1821
PLACE OF BIRTH Putschirn , Bohemia
DATE OF DEATH July 8, 1895
Place of death Vienna