The term adsorption is frequently encountered in the literature in connection with discussions concerning the reaction taking place between biotoxins and tissue-cells and between toxins and antitoxins. Regarding the reaction occurring between staphylohemolysin and red blood cells, Forssman (1) stated that as a rule no adsorption of the lysin by the sensitive cells takes place. He remarked further that instances in which adsorption was seemingly observed by him have no significant bearing upon the nature of the process of staphylohemolysis. However, no record is found in the literature of attempts to formulate the quantitative relationship between staphylococcal toxin and red blood cells in terms of an equation. In order to determine the course of partial staphylotoxin-neutralization by the corresponding antitoxin, Burnet (2) carried out a number of preliminary experiments to establish the relationship between the amount of free toxin and the degree of hemolysis produced.