White ceramic filter tube with nipple on one end and metal pipe-like case for the ceramic filter. Ceramic filter tube fitted into metal case so that only the ceramic nipple protrudes from one end.
Close-up of nipple end of ceramic filter tube and cylindrical metal fitting for filter case showing manufacturer's labels.

Pasteur Chamberland filter, early 20th century

Courtesy National Museum of American History

Bacterial filters were an essential tool for securing a supply of uncontaminated water and for purifying products in industrial applications. This porcelain filter, developed in Pasteur’s laboratory, had tiny pores that allowed fluids to pass through while holding back bacteria and other microorganisms.


Drawing of filter seated in metal pipe-like case with spigot on top, shown with a cut-away view of the same filter.

“Section and elevation of Chamberland’s filter” from Microbes, Ferments and Moulds, Edouard Louis Trouessart, 1891

Courtesy National Library of Medicine

Bacterial filters were an essential tool for securing a supply of uncontaminated water and for purifying products in industrial applications. This porcelain filter, developed in Pasteur’s laboratory, had tiny pores that allowed fluids to pass through while holding back bacteria and other microorganisms.