Preface to the First Edition.
In my text-book on Physiological Chemistry, published in 1906, I made an attempt to harmonize the defensive measures, adopted by the animal organism against products generated by cells out of harmony with the body, with the metabolic processes of the individual cells of the body. I was of the opinion that, when an invasion takes place of cells which are out of harmony with the body, the blood or plasma, and the cells, the cells of the body respond with counter-measures which are not entirely new to the cells of the particular organ or of the blood; on the contrary, I tried to bring the whole question of the so-called reactions of immunity into close line with processes that are normal, and consequently familiar, to the cells. From the point of view stated in the above-mentioned text-book, I attacked experimentally the problem of the method of defence, used by the animal organism, against the invasion of substances out of harmony with the body, the blood plasma, and the cells. In the first place I studied the question whether normal blood plasma contains definite ferments; and, in the second place, whether the introduction of disharmonious substances is followed by the appearance of ferments which were not there before. I found, in fact, that, after the
