Brownian Movement, a phenomenon discovered by Robert Brown, a botanist, in 1827. On viewing through a microscope a liquid such as gamboge solution, in which small particles are in suspension, these particles are seen to be in constant motion backwards and forwards without any regularity or co-operation. Brown suspected that the particles were living matter, but it has been shown by Gouy and Perrin that the phenomenon would follow from the molecular structure of matter, being produced by molecular bombardment arising from thermal agitation. In 1905 Einstein arrived at a satisfactory quantitative theory. The phenomenon is closely related to sedimentation equilibrium in an emulsion of very small particles. An equilibrium is reached in which the density of the particles decreases gradually with increasing height.
Robert Browne, (1550-1633), founder of the Brownists, born at Tolethorpe, near Stamford. Educated at Corpus Christi College, Cambridge, he was for a time a schoolmaster. He took orders, but his licence to preach was revoked when he began to attack and condemn the Established Church. So fiercely did he denounce its government that he was imprisoned in 1581 by order of the Bishop of Norwich, and released only through influence. After several imprisonments he retired to the Netherlands and formed a Church, which was not very successful and soon broke up. Meanwhile, in his Books which showeth the Life and Manners of all True Christians, he put forward the theory on which modern Congregationalism has been built up. After some years at Middelburg, he returned to Britain and stayed for some time in Scotland. He then returned to his home, and tried to spread his doctrines there. He again suffered imprisonment, but his attitude towards the Established Church changed, and he accepted a position at St Olave's Grammar School, and finally became vicar of a church in Northamptonshire. Here he stayed 42 years, but, always a man of violent temper, he was in 1630 imprisoned for an assault on a constable, and died in jail. His defection did not break up his sect. They survived in the Netherlands for a considerable time, and many migrated to America. In England they took the name of Independents or Congregationalists.