The book describes the work of fifteen years along a well defined line of thought. Those who have followed the publications from Vaughan's laboratory during these years know what opposition many of his beliefs have encountered, so that it is with real enthusiasm that one reads the clear, simple statement here presented. For it is obvious that almost all his tenets have been amply upheld by recent workers in immunity.
The preface contains a general consideration of the chemical forces that work in the living cell, and the introduction deals with the subject of the protein structure of bacterial cells. It is pointed out that like all other proteins, bacterial proteins can be split by chemical agents or ferments into a very poisonous portion and a non-toxic residue. The remnant of the book is concerned with a discussion of these split products and their relation to sensitization, immunity and