This article is within the scope of WikiProject Water, a collaborative effort to improve the coverage of Water supply-related subjects on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.WaterWikipedia:WikiProject WaterTemplate:WikiProject WaterWater articles
This article is within the scope of WikiProject Viruses, a collaborative effort to improve the coverage of viruses on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.VirusesWikipedia:WikiProject VirusesTemplate:WikiProject Virusesvirus articles
This article is within the scope of WikiProject Microbiology, a collaborative effort to improve the coverage of Microbiology on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.MicrobiologyWikipedia:WikiProject MicrobiologyTemplate:WikiProject MicrobiologyMicrobiology articles
This article is part of the History of Science WikiProject, an attempt to improve and organize the history of science content on Wikipedia. If you would like to participate, you can edit the article attached to this page, or visit the project page, where you can join the project and/or contribute to the discussion. You can also help with the History of Science Collaboration of the Month.History of ScienceWikipedia:WikiProject History of ScienceTemplate:WikiProject History of Sciencehistory of science articles
This article is within the scope of WikiProject Science, a collaborative effort to improve the coverage of Science on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.ScienceWikipedia:WikiProject ScienceTemplate:WikiProject Sciencescience articles
Some knowledgeable person should say how big the pores are in these filters. They played an important role in the discovery of viruses, which were originally called "filterable viruses" because liquids containing them remained infectious, even passing through these filters, whose pores were too small for bacteria to pass through.CharlesHBennett (talk)
The filters have different grades of porosity. Berkefeld Filters, made from kieselguhr, have three grades: V (viel) the coarsest, W (wenig) the finest and N (normal) in between these. Chamberland Filters, which are unglazed porcelain, are graded L1 the most porous, and L1a, L2 and L3, which correspond to Berkefeld V, N and W. I doubt that the inventors knew the average pore size, but the British Pharmaceutical Codex required filters to be able to trap Serratia marcescens, which indicates and average pore diameter of 0.5 microns and less than 0.75 microns. Later filters became more refined and up until the 1960s, the sizes of viruses were estimated by using filters that had pores measured in millimicrons. Graham Colm (talk) 10:05, 13 March 2014 (UTC)[reply]
.jpg){kind=small}
