Here, again, as in the case of the antitoxins, it must be admitted that the antitoxalbumin possesses a specific affinity by virtue of which it unites chemically with the toxalbumin to give rise to a new substance which is devoid of toxicity. The first antidiastase obtained by immunization methods, and according to the mechanism we have already seen, was _antiemulsin_, obtained by Hildebrandt.[62] This antiemulsin counteracts, both _in vivo_ and _in vitro_, the specific action of emulsin. These studies have been followed by a large number of scientists, particularly by Camus and Gley,[63] Carnot, Mesnil,[64] and Charron and Levaditi,[65] in the case of trypsin; and Sachs[66] in the case of animal pepsin. Gessard[67] obtained a very active _antityrosinase_, and Mohl an _antiurease_. [62] HILDEBRANDT: Weiteres über hydrolyt. Fermente, etc. _Virch. Arch._, CXXXI, 1895, P. 5. [63] CAMUS and GLEY: _Compt. rend. de la Soc. de Biolog._, 1897. [64] MESNIL: Sur la digestion des actinies. _Annales de l'Institut Pasteur_, 1901. [65] CHARRIN and LEVADITI: _Compt. rend. de l'Académie dest Sciences_, 1900. [66] SACHS: Ueber Antiseptika. _Zeitschr. f. Biolog._, 1901, XXVI. [67] GESSARD: _Annales de l'Institut Pasteur_, 1901, p. 609; _Comp. rend. de la Société de Biologie_, May, 1902. The most important researches regarding this subject have been published by Morgenroth, Briot,[68] and Korschum[69] on _antilab_ (or _antirennet_). The researches of these authors have fully demonstrated that there is considerable difference between the various rennets, which had heretofore been confounded under one head; thus there is no difference whatever between animal rennet and the rennet extracted by Rosetti[70] from Cynara cardunculus (cardoon) so far as their coagulant action on milk is concerned, yet each yields an antibody which is strictly specific to itself. From a scientific point of view we see, therefore, that the preparation of antidiastases permits us to differentiate certain diastases that could otherwise not be differentiated. [68] BRIOT: Thèse de Doctorat ès-Sciences, Paris, 1900. [69] KORSCHUM: _Zeitschr. f. physiolog. Chemie_, 1902, XXXI. [70] ROSETTI: _L'Orosi, giorn. di chemica, farmacia et scienza affini_, 1898. III. ANIMAL TOXINS. As we have shown at the beginning of this chapter, certain diastases, and particularly those that are concerned with the digestive processes, pepsin, trypsin, etc., and which are produced in abundance by the entire living organism, possess quite clearly defined toxic properties, and sometimes to even a considerable extent.[71] [71] GUSTAVE SAUX: De la toxicité des produits de la digestion peptique. _Thèse de doctorat_, Bordeaux, 1902.