CHAPTER XXIII 



CATALASES. TISSUE RESPIRATION 



CATALASES 



IN close connection with the discusssion of oxidizing 

 ferments the present lecture will be devoted first to the 

 catalases. Here, too, the task of presentation has been ma- 

 terially lightened by the fact that F. Battelli and Miss Stern, 

 who have themselves had an important part in the investiga- 

 tion of catalases, have critically reviewed all the literature 

 upon the subject in a recent monograph. 1 As this is readily 

 accessible to everyone the author may be permitted without 

 going into details to satisfy himself with sketching in the 

 main points. 



Definition of Catalases. The term catalase has been ap- 

 plied to ferments which are able to break up hydrogen per- 

 oxide into water and oxygen. As this oxygen is in molec- 

 ular form, and inactive, it is essential to clearly differentiate 

 the catalases from the oxidizing ferments. The name 

 "catalase" was originally given by Low (1901) ; but our 

 recognition of these substances goes back much farther. 

 Even Schonbein was concerned with them, and Thenard as 

 early as the beginning of the last century was aware of the 

 fact that tissues of the most varied type, as well as blood 

 fibrin and colloidal noble metals are capable of breaking up 

 hydrogen peroxide. The phenomenon was sufficiently con- 

 spicuous to prevent the catalases from fading out from the 

 perspective of physiological research. For a long time they 

 were confused with the oxidizing ferments, an error first 

 fully corrected by the investigations of Bach and Chodat. 

 Senter, who obtained the catalase of the blood free from 

 haemoglobin, proposed the name "haemase" for it; but such 



1 Literature upon Catalases : C. Oppenheimer, Die Fermente, 3d ed., 393- 

 408, 1909; F. Battelli and L. Stern, Ergebn. d. Physiol., 10, 531-597, 1910. 



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