ENZYMES. 47 



we must mention the two diamines, cadaverine or pentamethylenediamine, 

 C5Hi4N2, and putrescine or tetramethylenediamine, C4Hi2N2, which 

 have awakened special interest because they occur in the contents of the 

 intestine and in the urine in certain pathological conditions, especially 

 in cholera and cystinuria. 1 The putrefaction bases martitine, CgHigNs, 

 putrine, CnH^e^Os, and viridinine, CsH^^Os, isolated by ACKER- 

 MANN, also belong to this group. Of special interest is the bacterial 

 poison isolated by FAUST, 2 called sepsine, CsH 14^62, which is the sub- 

 stance producing the characteristic toxic action of putrefactive masses. 

 Sepsine was prepared by FAUST as a crystalline sulphate which, on repeated 

 evaporation of its solution, was readily converted into cadaverine sulphate. 



Of especially great interest are the toxines which are found in the 

 higher plants and animals, like the jequirity-bean and castor-seed, in 

 the poison of snakes and spiders, in blood-serum, etc., and particularly 

 those produced by pathogenic micro-organisms have an unmistakable 

 relation to the enzymes. A closer study of these various bodies, lysines, 

 agglutinines, toxines, etc., as well as of the anti toxines and the theory 

 of immunity, does not lie within the scope of this work, but on account 

 of the great importance of the subject it will be briefly discussed on 

 page 66. 



Classification of the Enzymes. If we exclude those processes which 

 are the result of several enzymotic reactions (i.e. autolysis, putrefaction) 

 then the most important enzymotic processes studied so far are the fol- 

 lowing : 



1. Hydrolytic cleavage processes. 



2. Cleavages of another variety (fermentation). 



3. Oxidations. 



We have no general chemical reaction in the ordinary sense which 

 is common to all enzymes or ferments and each enzyme is characterized 

 by its action and by the conditions under which this action is developed. 

 As the action of an enzyme upon a substance, or related substances, or 

 groups is limited therefore these substances or groups are called the 

 substrate of the enzyme. 



In regard to the terminology it must be remarked that an enzyme 

 is often named after the substrate (amylase, protease, lipase); in other 

 cases the kind of action determines the name (oxidase, reductase) and 

 finally one of the products produced by its action forms the basis for 

 the name (alcoholase) . 



1 See Brieger, Berlin, klin. Wochenschr., 1887; Baumann and Udransky, Zeitschr. 

 f. physiol. Chem., 13 and 15; Brieger and Stadthagen, Berlin, klin. Wochenschr., 1889. 



2 Faust, Arch. f. exp. Path. u. Pharm., 51; Ackermann, Zeitschr. f. physiol. Chem., 

 54 and 57. 



