A brief account of microscopical observations made in the months of June, July and August, 1827, on the particles contained in the pollen of plants; and on the general existence of active molecules in organic and inorganic bodies is an 1828 paper by Robert Brown, which describes his observations of the irregular movement of minute particles suspended in a liquid. Brown gives the results of a series of experiments, emerging from his study on the action of pollen, and compares this with the work of previous authors. The phenomenon he observed through his microscope, in both organic and inorganic substances, came to be known as Brownian motion.