Abstract
Since bacteria approach colloids in size and are negatively charged, it seemed logical that they should attract cations as represented by the equation, (Bacterial celln-)+nH+(Bacterial celln) (nH+). The several bacteria studied adsorbed such cations as H+, Hg++, Mg++ and methylene blue+. The magnitude of this capacity was 35-50 m.e. for H+ per 100 g. of bacteria (dry wt.). A proposed mechanism of adsorption is advanced. The relative adsorbability of different ions is shown.