It is very instructive to observe the adsorption phenomena during filtration through a powder First a colourless, then a yellow (carotene liquid flows out from the bottom of the funnel, while a bright green ring forms at the top of the inulin column, below which a yellow ring soon appears On subsequent washing of the inulin column with pure ligroin, both rings, the green and the yellow are considerably widened and move down the column M.S. Tswett Tr. Varsha Obshch. Estestvoispyt, Otd. Biol 14(1903)20It is very instructive to observe the adsorption phenomena during filtration through a powder. First a colourless, then a yellow （carotene） liquid flows out from the bottom of the funnel, while a bright green ring forms at the top of the inulin column, below which a yellow ring soon appears. On subsequent washing of the inulin column with pure ligroin, both rings, the green and the yellow, are considerably widened and move down the column. M.S. Tswett Tr. Varshav. Obshch. Estestvoispyt., Otd. Biol., 14 （1903） 20