Louis Pasteur: the first experimental aerobiologist

Pasteur is a well known scientific giant. However, it is not generally known that in less than a year, in 1860, he founded on precise scientific ground a new science: «micrography» (called Aerobiology since Meier's times (1930's). Not only did he definitely made the spontaneous generation theory disappear for ever, he also presented the true nature of the air spora: a limited cloud of solid dust dispersed by air movements and emptied by gravity. In order to prove the discontinuity of the supposely continuous spontaneous generation, he studied different localities at different seasons, and travelled at different heights. By doing so, he discovered most of Aerobiology's principles: 1) the absolute necessity of volumetric sampling; 2) the heterogeneity of the air spora; and 3) the aerobiological pathway (take-off, dispersal, deposition).