Franz Ulrich Theodor Aepinus

Born Dec. 2 (13), 1724, in Rostock; died Aug. 10 (22), 1802, in Dorpat, now Tartu. Russian physicist. Member of the St. Petersburg Academy of Sciences (1756). By nationality, a German.

Aepinus studied at the universities of Rostock and Jena. He was a privatdocent at the University of Rostock and, in 1755, was appointed a professor at the Berlin Academy of Sciences. He moved to Russia in 1757, becoming a Russian subject. In 1765, Aepinus became a tutor in physics and mathematics to the heir to the throne (the future emperor Paul I). In 1782 he was appointed a member of the Commission for Founding Public Schools; as a member of the commission, he drew up a plan that was adopted as the basis for the organization of primary and secondary education in Russia.

In 1756, Aepinus discovered and studied the phenomenon of pyroelectricity in tourmaline crystals. Using the ideas of B. Franklin and I. Newton, he developed a theory of electrical and magnetic phenomena and pointed out the similarity of such phenomena. Aepinus was the first to explain the phenomena of electrostatic induction and polarization. He proposed the concept of an electrophorus and predicted the oscillatory nature of a discharge from a Leyden jar. Around 1784, Aepinus built the first achromatic microscope.