Blas Cabrera (20.05.1878- 1.08.1945) was a Spanish physicist. He was born in Lanzarote (the Canary Islands). He graduated from the University of Madrid (1898), where he also worked (professor from 1905). In 1910 he was appointed director of the Spanish Institute of Physical Research and in 1932 of the National Institute of Physics and Chemistry (in 1910—12 he worked with P. Weiss at the Zurich Polytechnic). From 1936 he worked with A. Cotton in the magnetic laboratory of the University of Paris, and in 1941 —45 he was professor at the university in Mexico City.
His main work was in the field of magnetism. In particular, he studied the properties of electrolytes, the magnetic properties of substances and weak magnetism. He contributed to the theory of the molecular field, modified the Curie — Weiss law, derived equations for the atomic magnetic moment and improved many magnetic instruments. His research also concerned magnetochemistry.