CATALYSIS AND THE ENZYMES 



albumin. This substance was called Pepsin. 

 In rapid sequence followed the discovery of 

 Emulsin, which splits up the amygdalin contained 

 in almonds to prussic acid, benzaldehyde and 

 grape sugar ; the discovery of Myrosin in mustard 

 seeds, which produces mustard oil ; later on the 

 discovery of Invertin in yeast, which cane sugar 

 splits into its sugar components ; Trypsin in the 

 pancreas gland of quadrupeds, which rapidly 

 splits up albumin to amino-acids. Many other 

 discoveries were made later on, in connection 

 with which I only mention the important state- 

 ment of Schoenbein in Basel, that oxidising effects 

 are caused by substances which are soluble in 

 water, precipitated by alcohol and destroyed by 

 boiling. All these substances exercise their 

 activity, even when applied in very small quan- 

 tities. They are all of organic origin, never found 

 in inorganic nature, and not to be gained by 

 chemical synthesis. We do not wonder that such 

 effects caused by diastase and the other sub- 

 stances mentioned were not sharply distinguished 

 from the microbial processes of fermentation or 

 decomposition. We indeed see the expression 

 Fermentation used for both kinds of phenomena. 

 It was found sufficient to speak of Soluble Ferments 

 and of Microbic Ferments. 



Kuhne, of Heidelberg, was the first to propose to 

 change the nomenclature and to avoid speaking of 

 ferments. He clearly recognised that even the 

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