Robert Brown

Robert Brown (21 December 1773 in Montrose - 10 June 1858 in London) was a Scottish physician, surgeon and botanist trained at the University of Edinburgh. In addition to his mammoth work collecting Australia's flora, he is best remembered for coining the term "nucleus cell"; and for having discovered the movement of agitation of the particles on the surface of the water (called Brownian movement in his honor), although he was unable to determine its causes (the phenomenon would be explained in terms of molecular kinematics by Albert Einstein in 1905.) During three years he carried out a thorough investigation collecting about 3,400 specimens, of which about 2,000 were new to science. A part of this collection was lost on the voyage on the Porpoise, en route to London.

He remained in Australia until May 1807. For three years he researched the collected material. In 1810, he published the results of his collections in his work Prodromus Florae Novae Hollandiae et Insulae Van Diemen, the first taxonomic account of the flora of Australia.

Biography

Cover of the Prodromus.

He enlisted in the Fencibles regiment as a surgeon in 1795. He accepted a position aboard the Investigator as naturalist in charge of Mathews Findler, who was about to sail on a mapping voyage to Australia. During three years he carried out a thorough investigation, collecting about 3,400 specimens, of which about 2,000 were new to science. A part of this collection was lost on the voyage on the Porpoise, en route to London.

He remained in Australia until May 1805. For five years he researched the collected material. In 1810, he published the results of his collections in his work Prodromus Florae Novae Hollandiae et Insulae Van Diemen, the first taxonomic account of the flora of Australia.

He described some 1,200 species new to science from Western Australia.

In a scientific paper that he read at the Linnean Society (London) in 1831 and published in 1833, Brown named the nucleus of eukaryotic cells. The nucleus had already been observed before, perhaps as early as 1682 by the Dutch microscopist Anton van Leeuwenhoek. In 1802, Franz Bauer had drawn the nucleus as a normal feature of plant cells. But Brown was the one who gave it the name it bears to this day (giving credit to Bauer's illustrations). Both Bauer and Brown believed that the nucleus was not universal; and Brown thought it was confined exclusively to monocots.

In 1827, examining pollen grains, moss spores, and Equisetum suspended in water under a microscope, Brown observed minute particles with vacuoles in the pollen grains executing a continuous random motion. He later observed the same movement in dust particles, overturning his previous hypothesis that the movement was due to the fact that the pollen had life. He himself could not give an explanatory theory of this movement, later called Brownian movement in his honor.

Eponyms

Physics

The circulatory motion of particles in aqueous suspensions bears his name, Brownian motion, originally described in 1785 by Jan Ingenhousz in carbon particles suspended in alcohol. Marian Smoluchowski, almost simultaneously with Albert Einstein, described the phenomenon mathematically.

Botany

His name is commemorated in the Australian herbaceous genus Brunonia, and in numerous Australian species: Eucalyptus brownii, the moss Tetrodontium brownianum, a species he discovered while growing up in Roslin, Edinburgh while a student. It can still be seen at the site of his discovery.