Philipp von Jolly

Johann Philipp Gustav von Jolly (1809 to 1884) was a German experimental physicist who measured gravitational acceleration with precision weights and also worked on osmosis. He designed several instruments, among them the Jolly balance in 1864, a special eudiometer in 1878, his own air pump and the Jolly air thermometer. Born in Mannheim, the son of a merchant, he went to Heidelberg University in 1829 to study physics and mathematics, worked for a time in Vienna as a mechanician for factories and mining plants, and returned to Heidelberg in 1834, where he received his doctorate. He was appointed professor of mathematics there in 1839 and professor of physics in 1846, and in 1854 he moved to the Ludwig-Maximilians-Universitat Munchen, taking the position once held by Georg Simon Ohm, and was knighted in the same year. He was initially skeptical of Julius von Mayer's theory on the mechanical equivalent of heat. His son was the neurologist Friedrich Jolly.