The mechanism of isohemagglutination has been interpreted in different ways by the various investigators of this phenomenon. The assumption of differences of affinity as explanatory of the purely chemical nature of such antigen-antibody reactions, as Ehrlich hypothecated, has given way to the widely accepted principle that these bodies are of colloid nature and their interactions analogous to those of colloids in general. On the other hand, Gay (1) has offered the explanation that these reactions are governed by physicochemical laws; but this conception has not been supported by sufficiently convincing proof to warrant its acceptance.
Bordet (2) showed that bacterial agglutinins can be absorbed and specific agglutinins isolated by this method. The absorption of hemagglutinins was demonstrated by Malkoff (3), and later by Hektoen (4); since then, this has been observed repeatedly by others.
Read before the twentieth annual meeting of the American Association of Pathologists and Bacteriologists, New York, April 2, 1920.