SIGNIFICANCE OF THE CATALASES 559 



2 = 2 Pt ; PtO + H 2 2 = Pt + H 2 + 2 ) . According 

 to Schade, 6 however, an intermediate oxide formation does 

 not occur, and, too, the phenomena are not the resultant 

 manifestations of a great surface development as believed, 

 but the action of electrical forces. In differentiation between 

 the action of catalases and colloidal metals special point has. 

 been made of the difference in sensitiveness to high tempera- 

 tures, and of the fact that the action of catalases is strictly 

 specific, while colloidal metals may not only dissociate perox- 

 ide of hydogen but may also blue tincture of guaiac, set free 

 iodine from hydriodic acid, etc. An interesting analogy is 

 seen in their behavior with cyanogen which paralyzes cata- 

 lases as well as colloidal metals, and in each instance when 

 it is driven off the catalyzing power reappears. 7 



Physiological Significance of the Catalases. Important 

 as all this may be to the physical-chemist, the special interest 

 from our standpoint lies in the question of the role played by 

 the catalases in the play of interchange of forces actively 

 engaged in the living body. 



It was once hoped that an answer to this question would 

 be forthcoming from comparison of the catalase contents of 

 tissues in a wide group of physiological and pathological 

 conditions ; but unfortunately very little of value has been 

 attained. 



The commonly expressed view that the amount of cata- 

 lases in the tissues is an index of the intensity of the com- 

 bustion processes therein is shown to be untenable directly 

 by the fact that, as proved by Battelli and Stern, the tissues 

 of the adder and toad are even richer than the tissues of 

 warm-blooded animals in catalases; and, too, muscles, in 

 spite of their marked respiratory activity, show but a small 

 proportion of catalases. 8 The presumption of a parallelism 

 between the proportions of catalases and peroxidases in 



H. Schade (Kiel), Zeitschr. f. exper. Pathol., 1, 603, 1905. 



' Cf. O. Low, Centrabl. f. Bakteriol., II, 21, 1, 1908; T. Bokorny, ibid., 193. 



8 Cf. also E. J. Lesser ( Halle ), Zeitschr. f. Biol., 49, 575, 1907. 



