ABSTRACT
In a characteristic way Charles Richet's love of travel became entangled with his literary and scientific endeavors in an adventure from which his most important contribution to physiology emerged. Richet set up a plan to study the beasts based on his earlier work in which repeated exposure of bacteria to metallic salts yielded eventual immunity to the poison. Richet thought that it might be possible to adapt animals and man to the effects of poisons, by initially injecting an extremely small quantity of the substance and then gradually increasing the dose. Richet demonstrated that blood serum from the animal previously injected with the poison produced anaphylaxis on the first injection into the second animal. Richet's discovery of anaphylaxis with its seeming relevance to immunity had enlarged the field of immunology beyond microbes and had set off an intense flurry of activity among investigators in Europe and America.
