Robert Brown

Born in Scotland on 21 December 1773, Brown trained as a botanist and sailed to Australia with Matthew Flinders, returning with specimens that reshaped plant taxonomy and established dozens of genera still recognized today. His microscope work in the decades that followed broke new ground: he described the cell nucleus and cytoplasmic streaming in unprecedented detail, distinguished gymnosperms from angiosperms for the first time, and advanced early studies of pollen and fertilization. The jittering motion of particles he observed in 1827 - Brownian motion - would later help prove atoms exist. He died in London on 10 June 1858, leaving a body of work so precise that botanists still mark his names with the abbreviation R.Br.