Template:Selected anniversaries/March 19
1610: Painter Hasegawa Tōhaku dies. Hasegawa Tōhaku founded the Hasegawa school and one of the great painters of the Azuchi–Momoyama period (1573-1603). He is best known for his byōbu folding screens, such as Pine Trees and Pine Tree and Flowering Plants.
1816: Physician and activist Filippo Mazzei dies. Mazzei acted as an arms purchasing agent for Virginia during the American Revolutionary War.
1928: Physicist and geophysicist Emil Wiechert dies. Wiechert made contributions to both fields, including presenting the first verifiable model of a layered structure of the Earth, and being among the first to discover the electron.
1978: Mathematician Gaston Maurice Julia dies. Julia devised the formula for the Julia set, which consists of values such that an arbitrarily small perturbation can cause drastic changes in the sequence of iterated function values. Julia's work later proved foundational to chaos theory.
1987: Physicist and academic Louis de Broglie dies. De Broglie postulated the wave nature of electrons and suggested that all matter has wave properties. He won the Nobel Prize for Physics in 1929, after the wave-like behavior of matter was first experimentally demonstrated in 1927.