Alexander Alexandrovich Eichenwald (4.01.1864—1944) was a Russian physicist and an academician of the Academy of Sciences of the Ukrainian SSR (1919). He was born in St Petersburg. He graduated from the St Petersburg Institute of Railway Transport Engineers (1888). In 1897 he received the degree of Doctor of Philosophy at the University of Strasbourg. From 1897 he worked at the Moscow Engineering School (in 1905 —08 as director), and at the same time taught at other institutions of higher education in Moscow, in particular at Moscow University (1906 — 11 and 1917-20). From 1920 he lived abroad.
His work concerned electricity, optics and acoustics. In 1903 he was the first to establish experimentally the existence of a magnetic field in the motion of electrified bodies, and by precise measurements proved the equivalence of convection currents and conduction currents; he was also the first to detect in an experiment the existence of the magnetic field of the displacement current (the Eichenwald experiment). In 1908 he clarified the question of the nature of total internal reflection of light. He is known as a brilliant lecturer and a first-class demonstrator, and as the author of the textbooks “Electricity” and “Theoretical Physics”.