Studies on the Chemistry of Anaphylaxis (III). Experiments with Isolated Proteins, Especially those of the Hen's Egg

In the early history of immunology the few preliminary attempts to secure precipitins differentiating different proteins coming from the same animal were so generally unsuccessful that, in spite of some more or less positive results, the opinion became general that the specificity of proteins depends upon certain groups or radicals which are characteristic of the origin of the protein, and perhaps not associated with demonstrable chemical differences. With