562 CATALASES 



the peroxidases, 12 it should be stated in contravention that 

 Bach and Chodat hold that in setting up a system of H 2 2 + 

 peroxidase + oxidizable substance + catalase, the catalase 

 can not disturb in the least the oxidizing action of the per- 

 oxidase, but breaks up only the remnant of peroxide of 

 hydrogen, which was not consumed by the peroxidase. 13 



Finally, contrary to the belief of Jolles 14 and Ewald 15 

 that catalases are able to facilitate the separation of oxygen 

 from oxyhaemoglobin, it may be regarded as proved (from 

 the studies of E. v. Czyhlarz and the author) 16 that power- 

 fully active catalases are incapable of accelerating the oxida- 

 tion of ammonium sulphide by oxyhaemoglobin, as well as 

 of phenolphthalin by hydrogen peroxide in the presence of 

 hsematin. There is, therefore, no basis whatever for assum- 

 ing an oxidizing power for the catalases. 



In reviewing the above, it must in honesty be acknowl- 

 edged that we not only know nothing positive about the 

 physiological operation of the catalases, but also that we do 

 not even know whether they have any important physio- 

 logical significance at all, and whether they may not perhaps 

 be altogether accidental and non-essential. Each year in 

 his lectures the author is in the habit of presenting before 

 his students the experiment in which a few drops of blood 

 are placed in a large beaker glass and drop by drop hydro- 

 gen peroxide is added. The audience wonders and is 

 pleased as the reaction fiercely goes on with a violent and 

 voluminous production of froth ; and the lecturer also w^on- 

 ders and is pleased at the remarkable and imposing mani- 

 festation of nature. But does this say that the phenomenon 

 has any part in the vital processes ! May it not be thought 

 that physiologists are "obsessed" by the catalases by the 

 very fact of their imposing appearance ? The author would 



" A. Herlitzka, Rendic. Accad. del Lincei, 16, 473, 1907, and earlier papers. 



M Cf . Battelli and Stern, 1. c., p. 594. 



"A. Jolles, Fortschr. d. Med., 22, 1229, 1904. 



" W. Ewald, Pfliiger's Arch., 116, 334, 1907. 



16 E. v. Czylharz and 0. v. Fiirth, Hofmeister's Beitr., 10, 389, 1907. 



