succeeded in supplying definite proofs for such a view. It is only recently that experiments have been made, by means of injections of peptones and derivatives of amino-acids, especially of amines, with a view to producing phenomena resembling those of an anaphylactic shock. It is difficult to decide with any certainty what part is played, by the ferments we have observed, in the setting up of anaphylaxy. Several facts run counter to the supposition of a direct relation between the presence of active ferments and the particular substrate against which they are directed. It has been proved, beyond doubt, that these ferments exist in the blood at a time when the anaphylactic shock cannot yet be produced by a second injection of the same material as was used in the first case. Further, it has already been pointed out that these ferments are specific only in respect of the group of substances which are used for the injection, but not for the particular body that has been introduced. To produce the shock, on the contrary, the substrate, with which the animal under experiment was rendered sensitive, must be present. A certain importance, in regard to the setting up of the state of shock, may be attached to the power possessed by the plasma of decomposing albumen; as is shown by an observation which was made by Hermann Pfeiffer and confirmed by ourselves, according to which the proteolysis in the plasma disappears during the
