Franz Aepinus


Franz Ulrich Theodor Aepinus was a German and Russian Empire natural philosopher. Aepinus is best known for his researches, theoretical and experimental, in electricity and magnetism.

Life

He was born at Rostock in the Duchy of Mecklenburg-Schwerin. He was descended from Johannes Aepinus, the first to adopt the Greek form of the family name Hugk or Huck, and a leading theologian and controversialist at the time of the Protestant Reformation. After studying medicine for a time, Franz Aepinus devoted himself to the physical and mathematical sciences, in which he soon gained such distinction that he was admitted a member of the Prussian Academy of Sciences. In 1755 he was briefly the director of the Astronomisches Rechen-Institut. In 1757 he settled in St Petersburg as member of the Russian Academy of Sciences and professor of physics, and remained there till his retirement in 1798. The rest of his life was spent at Dorpat.
He enjoyed the favor of Empress Catherine II of Russia, who appointed him tutor to her son Paul, and endeavoured, without success, to establish normal schools throughout the empire under his direction. In 1761, Aepinus was elected a foreign member of the Royal Swedish Academy of Sciences.
In 1764, he was appointed as a head of the cryptographic service of Russia, and held this position till 1797, during 33 years.

Works

His principal work, Tentamen Theoriae Electricitatis et Magnetismi, published at St Petersburg in 1759, was the first systematic attempt to apply mathematical reasoning to these subjects.
He also published a treatise, in 1761, De Distributione Caloris per Tellurem, and he was the author of memoirs on different subjects in astronomy, mechanics, optics and pure mathematics, contained in the journals of the learned societies of St Petersburg and Berlin. His discussion of the effects of parallax in the transit of a planet over the sun's disc excited great interest, having appeared between the dates of the two transits of Venus that took place in the 18th century.

Electrical theories

Aepinus and Henry Cavendish devised theories of electricity which were essentially the same, yet had been framed without any communication between these two philosophers. Aepinus however published his theory about ten years before that of Cavendish. These are essentially modern theories which eventually put to rest the idea of two fluids.
, Tartu, Estonia
Their theories said that
Cavendish and Aepinus believed that the electric fluid was
In effect, they are imagining the 'electric fluid' as consisting of electrons with almost no mass, but still with substantial electrical attractive and repulsive power. Static electricity then becomes a matter of a superabundance of electrons in one body, and a shortage of electrons in another.