Hermann Blau (21 January 1871 – 18 February 1944 ) was a German engineer and chemist, and inventor of Blau gas. Blau, a student of the Nobel Prize–winning chemist Adolf von Baeyer was originally a pharmacist but devoted himself in later life entirely to chemistry. His attempts to separate gas mixtures by physical means eventually led to the great invention of his life, a transportable liquid lighting gas from the distillation of gases.