Burdon-Sanderson in England in 1871 demonstrated the presence of bacteria in water; and Miquel at Paris in 1880 developed the first exact methods for enumerating them. In 1885, Percy Frankland used Koch’s procedures in a study of London water supplies and in 1887 Plagge and Proskauer reported on the bacterial purification effected by the filters of Berlin.
Pierre Miquel (1850–1922) was one of the fathers of Aerobiology, which he called Atmospheric Micrography. After studying both Pharmacy and Medicine, he decided to investigate, under strict protocols, the living organisms of the atmosphere, brought to light by Pasteur some 20 years earlier. All his aerobiological work was done at Paris Montsouris Observatory where he was ‘chief micrographer’ for 34 years. He was an active promoter of using only volumetric methods, and an early believer in ‘micrography statistics’. His most important works dealing with aerobiology were related to weather influences on atmospheric bioaerosols and on their impacts on epidemic diseases.