Antagonism of Ions

the ability of ions found in solution and carrying electrical charges of the same sign to mutually suppress each other’s inherent actions. The antagonism of ions is especially clearly manifested in living organisms and in the coagulation of colloid systems. For example, Na⁺ ions in the concentration in which they are found in biological fluids are poisonous to many simple organisms and isolated animal organs; however, upon addition of the proper concentration of K ⁺ or Ca²⁺ ions, the poisonous nature of the Na+ ions is suppressed. The solutions in which the harmful activity of any ions is eliminated by the action of antagonist ions is called physiologically equilibrated; such solutions are saline solution, seawater, and the fluids bathing cells and tissues of living organisms. Nutritive mixtures for plants are also equilibrated solutions. The antagonism of ions is one of the factors having a great significance in the formulation of the theory of plant nourishment and in the well-grounded use of fertilizers. The mechanism of the antagonism of ions has not yet been clarified, but it is apparently connected with active ion transport through biological membranes.