Immunity is now one of the most important phases of modernmedicine. In order to understand the process of immunity or antianaphylaxis we must understand anaphylaxis, a condition which precedes immunity. Prophylaxis depends on anaphylaxis. Recent work has done much to advance our knowledge of anaphylaxis, although there remains much to be made clear. The name "anaphylaxis" was given by Richet in 1904. and was used to define the condition of acquired or congenital hypersusceptibility of an organism to a strange protein, or antigen with a reaction body formed in the body of the organism undergoing immunity.1 The substance must be protein in nature, though not all of them will cause anaphylaxis (e. g., leucin and tyrocin).
For example, if we give a normal guinea-pig a sensitizing dose of 0.1 c.c. of horse-serum subcutaneously, intravenously, or intracranially, and after a period of from seven to nine days give this sensitized