In 1897, Wierusz-Kowalski hired
Ignacy Mościcki as his assistant. Mościcki created an electric arc method for fixing nitrogen, and he and Wierusz-Kowalski set up an experimental plant around 1903, trading nitric acid as the Société de l'acide nitrique. Wierusz-Kowalski's major fields of study were
lightning and
electrical discharge,
luminescence and
phosphorescence. Wierusz-Kowalski examined mixtures of
rare-earth metal compounds such as
alkali under the influence of
ultraviolet radiation, studying the phosphorescence of rare-earth compounds and organic compounds. In 1910, he discovered the phenomenon of progressive phosphorescence in the phosphorescence spectra of organic molecules. For his work in this field he was distinguished in 1912 by Harvard University. He was actively involved in the
Warsaw Scientific Society, which was founded in 1907. During World War I he worked with the Committee in Support of Victims of War in Poland, founded by
Henryk Sienkiewicz in
Vevey. The early 1900s were a time of great unrest in Polish politics and education. In 1912 Kowalski became a member of the
Academy of Sciences and Letters in Kraków. In 1915, Józef Wierusz-Kowalski was one of the lecturers of physics at the Physics & Mathematics Faculty of the TKN, a secular “free university” which later became Wolna Wszechnica Polska (
Free Polish University). In 1916 he was a member of the Board of the Association of Polish Education. The
University of Warsaw was reopened on 15 November 1915 as a Polish institution. A Section of Experimental Physics was opened in 1916 as part of the Department of Philosophy, under Wierusz-Kowalski's leadership. In January 1919 Józef Wierusz-Kowalski helped to found the Warsaw Physical Society. In 1919 Józef Wierusz-Kowalski entered the diplomatic service of Poland, On 19 October 1921 he was appointed deputy of Poland at The Hague, where he remained until 1 December 1924. He was a member of the
International Committee on Intellectual Cooperation of the
League of Nations. He then became the Polish ambassador in
Vienna, Austria, holding the position until 30 September 1926. On 21 October 1926 he became a representative of the Republic of Poland in
Ankara, Turkey, where he died. ==See also==