In 1834 he received his medical doctorate at
Prague, and several years later he obtained his
habilitation for
balneology (1841). Later on, he became a professor at the
University of Prague, where in 1862–1863 he served as university
rector. In 1862 he was appointed Landesmedizinalrat, and in 1865 became Hofrat (councilor) and a personal physician to
Franz Joseph I of Austria. A foundation arranged by Löschner resulted in the creation of the Franz Joseph Kinderhospital in Prague.
Löschner is remembered for his work in the field of
balneology. He advocated the curative properties of health spas, and wrote numerous articles promoting the
spas of
Bohemia. These publications were instrumental in making Bohemian spas a popular tourist destination, particularly the resorts at
Karlovy Vary and
Bílina, which were regularly visited by members of European royalty.