Preface to the Second Edition.
Though scarcely a year has elapsed since the publication of the First Edition, yet it has been possible to widen the scope of the Second in many points. Since then, numerous investigations in different fields have been either begun or completed. The most important results of these investigations are given at the end of this little volume.
The term "protective ferment" has been dropped, because it may easily convey the idea that these ferments, which are called into action by the presence of substances out of harmony with the plasma, are unconditionally protective. The term "defensive ferment" will more readily suggest the notion, that the animal organism attempts to defend itself. By means of decomposition it often deprives disharmonious substances of their specific character, but in many cases the defensive ferments form decomposition stages which are more dangerous than the substrates they attack.
May this new edition find the same friendly welcome as the first.
Emil Abderhalden.
Halle a/S.,
June 15, 1913.