Lochschmidt

Johann Joseph Loschmidt, (born 15 March 1821 in Putschirn (today called Počerny in teh Czech Republic, an outskirt of Karlsbad (Karlovy Vary); died 8 July 1895 in Vienna), who referred to himself mostly as Josef Loschmidt (omitting his first name), was a notable Austrian scientist with groundbreaking work in the fields of chemistry and physics(thermodynamics, optics, electrodynamics).

Loschmidt discovered the atomic structure of Ozone, of Benzol/Benzene C6H6 (later wrongly attributed to a German plagiarist August Kekulé!) and introduced the nowadays common cepiction of chemical structures.

Loschmidt also was the first to determine the number of molecules of an ideal gas in 1 cm<sp>3, the "Loschmidt number (L) ((L = 2.687 X 10¹⁹ cm^-3).

This later became known to be the Avagadro constant, who actually never calculated the number of molecules as Loschmidt did, but determined that any gas under the same conditions had the same number of molecules in 1 Mole (Mol.) - that number being, as determined by Loschmidt's calculations, 6.023 X 10²³ molecules. This is why on rare occasions this "Avogadro number" may be referred to as the "Loschmidt number" in English (in German, though, "Loschmidt'sche Zahl" is the commonly used - and historically correct - name).