Robert Brown, botanist and plant geographer, died on the 10th of June, 1858.
Robert Brown was a botanist and is often credited with being the originator of the science of plant geography. He was certainly acknowledged as the leading British botanist during the first half of the 19th Century. Brown’s study of the flora and fauna of Australia made him eminently respected in his field and he became a Fellow of the Royal Society and of the Linnean Society. The result of that work was Brown’s famous book about the flora and fauna of New Holland and Van Deimen’s Land as Australia was then known. Although Brown was also responsible for discovering the nucleus of a cell and indeed for having coined the word nucleus, he is perhaps best known for his discovery of the random movement of microscopic particles in a surrounding solution. That infinitesimal activity was later referred to as ‘Brownian motion’ and in fact provided the first evidence of the existence of atoms.
Robert Brown was born in Montrose on the 21st of December, 1773, the son of an Episcopalian minister. Although he later discarded his religious faith, Brown gained an appreciation for high intellectual standards from his father. He attended Montrose Academy then, in 1787, he went to Marischal College in Aberdeen as Ramsay scholar. Brown moved to Edinburgh with his family, in 1789, and studied medicine at the University of Edinburgh. He did not take a degree, but he did show a special interest in natural history.
In 1795, he joined the Fifeshire Regiment of Fencibles as Ensign and Surgeon’s Mate, and was posted to Northern Ireland. Brown’s journal entries during that period suggest that his military duties did not demand much of his time and, not being a man given to wasting time, Brown’s intellectual curiosity led him to study the German language. He also continued his botanical pursuits, memorising the structures of various plants, such as ferns and mosses. His knowledge of German later helped Brown recognize a significant scientific work in that language; ‘Geheimniss der Natur im Bau und in der Befruchtung der Blumen’, by C. K. Sprengel (1793) and bring it to the attention of fellow scientist, Charles Darwin, in 1841.
In 1800, Brown volunteered to serve as the naturalist on board HMS Investigator during the circumnavigation of Australia under Matthew Flinders. When Mungo Park refused to go, Sir Joseph Banks, president of the Royal Society, offered the post to Brown, with whose intellectual tenacity he was most impressed. Brown accepted with alacrity, though Banks had to apply pressure through the Lord Lieutenant in Dublin to procure Brown’s release. As a result, Brown was able to keep his commission and pay, and to receive from the Admiralty a salary of £420, which enabled him to continue supporting his widowed mother, in Edinburgh. The historic expedition to chart the coast of Australia arrived off what is now Western Australia in December, 1801.
During Flinders’ coastal surveys, Brown collected many species of plants and made it back to England, despite being shipwrecked in HMS Porpoise on the Great Barrier Reef and the Investigator having been condemned as unseaworthy. By the time he returned to London, in 1805, he had collected over 4,000 samples of plants, supplemental drawings, and specimens for zoological research. Banks convinced the Admiralty to give Brown a salary for classifying and describing his collection, which included 2,200 species of plants, at least 1,700 new species, and 140 new plant genera. The task took Brown an additional five years.
Finally, in 1810, Brown published ‘Prodromus Florae Novae Hollandiae et Insulae Van Diemen’, his study of the flora and fauna of New Holland and Van Deimen’s Land. The study modified one of the prevailing systems of plant classification (the Jussiaean system) by adding new families and genera and including observations about plants worldwide. The fame of Brown’s ‘Prodromus’ rests partly on its quality and partly on his modification of the ‘natural’ system of plant classification of Jussieu, rejecting the more rigid Linnaean practice and helping to revitalise botanical science in the process.
His discovery, in 1827, of the phenomenon he named ‘Brownian motion’ was published in a pamphlet the following year. Under a microscope, he noticed that living pollen grains of ‘Clarkia pulchella’ seemed to be darting around in a random manner. He then examined both living and dead pollen grains of many other plants, and also experimented with organic and inorganic substances, all reduced to a fine powder and suspended in water. The continuous molecular agitation he observed was not limited to living matter and revealed such motion to be a general property of matter in that state. Brown’s discovery provided the first evidence that proved the existence of atoms.
Another of his famous discoveries was published in an 1833 paper, in which Brown became the first person to note the existence of, and describe in detail, the nucleus (a term he coined) of plant cells. This arose when he was investigating the fertilization of Orchidaceae and Asclepiadaceae. In addition, Brown was the first to recognise the fundamental distinction between the conifers and their allies (gymnosperms) and the flowering plants (angiosperms).
In 1827, Brown became Keeper of the Banksian Botanical Collection at the British Museum. Throughout his life, Brown was held in high regard by his contemporaries, being known as ‘Botanicorum facile princeps’ (the pre-eminent botanist) by von Humboldt. Charles Darwin, a peer of Brown’s, remarked on the “minuteness of [Brown’s] observations and their perfect accuracy.” Darwin claimed that when Brown died, much of his knowledge “died with him, owing to his excessive fear of never making a mistake.”
Robert Brown died in Soho Square, in London, on the 10th of June, 1858, and was buried at Turnham Green. In 1876, his personal collections were acquired by the British Museum. A number of the plants he discovered in Australia were named after him, as was Brown’s Tetrodontium Moss, which he discovered at Roslin near Edinburgh while a student. Brown’s River, in Tasmania, is also named after him. His death led to a free date at the Linnean Society, which was filled by Charles Darwin’s lecture on the Theory Of Evolution.