654 



SCIENCE. 



[N. S. Vol. XII. No. 302. 



mass action, reverse the reactions and bring 

 about the corresponding synthesis. Every 

 one knows that the amount of glucose in 

 the blood is practically constant. When, 

 through the assimilation of carbo-hydrates 

 the glucose in the blood of the portal vein 

 rises above the normal, the liver cells con- 

 vert it into glycogen and store it away. As 

 soon as the glucose in the blood begins to 

 fall below the normal, as in the condition 

 of hunger, the glycogen begins to break up 

 and pass into the circulation. The decom- 

 position of the glycogen is presumably due 

 to the action of some enzyme, and it is en- 

 tirely possible that it is the same enzyme 

 which produces the synthesis as well as the 

 decomposition. If by any process we could 

 remove the maltose from our dextrose-mal- 

 tose solution as fast as it is found, the trans- 

 formation would finally be complete. The 

 glucose-glycogen cycle is doubtless equally 

 subject to the law of mass action. 



Not only is the subject of catalysis of 

 immense importance in the study of the 

 normal physiological processes. In another 

 respect it has an equally important beai'ing. 

 In recent years the toxines have assumed 

 a prominent role in pathology. How is it 

 that a chemically insignificant portion of a 

 substance may work such enormous changes 

 in the system ? This can hardly be attrib- 

 uted to chemical action in the ordinary 

 sense. Much more likely is it that the ac- 

 tion of the toxine is catalytic, simply con- 

 sisting in producing rapidlj' changes which 

 without it would require time of almost 

 indefinitely great duration. I have spoken 

 of negative or retarding catalysis. The 

 antitoxine is, perhaps, not to be regarded 

 as chemically neutralizing the toxine, but 

 rather as a retarding catalyzer, as one 

 tending to retard the changes which the 

 toxine would otherwise bring about. JSTot 

 only the toxines and antitoxines, but many 

 drugs which exercise an influence alto- 

 gether out of proportion to their amount. 



may act as catalyzers rather than strictly as 

 chemical reagents. In fact, it is not impos- 

 sible to imagine that the scientific medicine 

 of the future may be influenced largely by 

 a better understanding of this remarkable 

 phenomenon of catalysis. 



I would call the attention of those inter- 

 ested in the subject of enzj'mes and toxines 

 and antitoxines to the recent remarkable 

 paper of Bredig and von Berneck on in- 

 organic ferments,* which although essen- 

 tially inorganic appears to be an important 

 contribution to physiological chemistry. 

 Hydrogen peroxide is a substance particu- 

 larly susceptible to the action of catalyzers ; 

 its decomposition is expressed by the equa- 

 tion 



2HA=2H,0 + 0,. 



Among the substances which bring about 

 this decomposition without themselves 

 undergoing any perceptible change are 

 platinum, gold, silver, and many other 

 metals, the peroxides of manganese, lead 

 and cobalt and certain enzymes. Schon- 

 bein f says, speaking of the enzymes : 

 " It appears to me to be a highly remark- 

 able fact that all these fermenting or cata- 

 Ij'tic substances also have the property of 

 decomposing hydrogen peroxide after the 

 manner of platinum, a coincidence in vari- 

 ous activities which must give rise to the 

 suspicion that all depend upon a common 

 cause." And elsewhere :J " The results of 

 my most recent investigations have only 

 served to strengthen my conviction, long 

 since expressed and often repeated, that 

 the decomposition of hydrogen peroxide 

 by platinum is the prototype of all fer- 

 mentations." § 



*Zeii. phpsik. Chemie, 31. 258. 



■f Jouni. prakt. Chemie [1], 39. 334. 



tibid [1], 89. 335. 



? Whether or not the view of Loew (personally 

 communicated ) be true or not, that the action of most 

 enzymes on hydrogen peroxide is due to contamina- 

 tion by a special enzyme caialase, does not affect the 

 significance of Schonbein's statement. 



