In vitro investigations have shown that the adsorption capacity of activated charcoal ('Kohle-Compretten', 'Ultracarbon', E. Merck, Darmstadt, FRG) is just as high as that of 'Fuller's earth' (Surrey powder, Laporte Industries Ltd., Luton, GB) or 'Bentonite BP W.B. (Steetley Minerals Ltd., Milton Keynes, GB). Fuller's earth ('Fullererde') from another manufacturer has had very poor adsorption properties and is thus not suitable for the treatment of paraquat poisoning. Animal experiments have shown that the curative effect of activated charcoal given 0.5, 1, 2, and 3 h after ingestion of 200 and 300 mg paraquat/kg body weight is equally as good or even better than that of 'Fuller's earth' or 'Bentonite BP W.B' Activated charcoal is a substitute of equal value to these mineral soils.