Johann Josef Loschmidt
(Johann) Joseph ( or Joseph ) Loschmidt ( born March 15, 1821 in Putschirn, Bohemia, † July 8, 1895 in Vienna) was an Austrian physicist and chemist.
Life
Josef Loschmidt ( he used all his life, only his middle name and is also known in the literature only under Joseph Loschmidt ) was born to poor farmers in Putschirn in Carlsbad. On the advice of the priest Adalbert Czech, he received an education that in Ostrov ( 1833-1837 ) led him to the school on Piarist to Prague, where he went in 1839 to the German -speaking university. Here he came up with Franz Serafin Exner, a professor of philosophy in Prague in touch. At the suggestion Exner's back, trying to apply to psychological issues Loschmidt mathematical models. Although this project failed, but Loschmidt was thus a good mathematician. In 1841 he went to Vienna, where he graduated in 1846 in Physics and Chemistry from the Polytechnic Institute. After he failed to find a scientific body, he first worked in a steel factory, before he founded a company for the production of potassium nitrate in Vienna. This company went bankrupt but what he worked as a teacher at a secondary school in Vienna in 1856. In 1866 he got a job at the University of Vienna, where he was assistant professor in 1868, before he was from 1872 to 1891 Professor of Physical Chemistry. He was also the professor of Ludwig Boltzmann.
At the age of 66 years Loschmidt married his housekeeper Karoline. Shortly afterwards, in 1887, Loschmidt's only child Joseph was born, which, however, still died in infancy 1889. The dedicated honorary tomb of the family is located in Vienna's Central Cemetery ( 56B -2 -23).
In 1953 in Vienna Floridsdorf ( 21st district ) was named the Loschmidtgasse after him. 2010, the Large Lecture Hall II of the Chemical Institute of the University of Vienna was renamed Joseph Loschmidt auditorium.
Services
He conducted research in the areas of thermodynamics, electrodynamics and optics and crystal forms. In 1861 he made the first proposals for the constitution of benzene as an annular structure.
In 1865, he certain - on gaskinetischer basis - for the first time the size of the air molecules. He was also able to calculate for the first time later named after him Loschmidt constant that can be converted for use today Avogadro constant.
In his work " Chemical Studies / Constitutions formulas of organic chemistry in Graphs " (published 1861) described Loschmidt 368 ( of which 121 are aromatic ) molecules with the help of his " Constitution formulas ", these are still very well understood by chemists and show the spatial orientation of the atoms. His formulas show double or triple bonds with an appropriate number of strokes, as it is now more usual. Also included are formulas for ozone and that - only 21 years later officially discovered by August friend - cyclopropane. Loschmidt wrote that for phenyl rings probably similar constitutions were to accept as for cyclopropane, so he probably knew from the annular appearance of benzene. He described phenyl radicals as a construct of six carbon atoms, which may be regarded as hexavalent element. Kekulé knew Loschmidt " Constitution Formulas" before he published his version of the structure of the benzene ring, so some historians believe that Kekulé had at least his inspiration for the structure of the benzene from Loschmidt's work.
Because of his achievements, he membership of the Vienna Academy of Sciences was awarded.
In 1995, the Austrian Postal Administration on the occasion of the 100th anniversary of the death of Josef Loschmidt a commemorative stamp with a nominal value of ATS 20, - out.