CHAPTER VIII 

 CATALYSIS AND THE ENZYMES 



IN the beginning of the last century chemists 

 made the acquaintance of a series of re- 

 markable phenomena, which were caused by 

 finely divided metals, particularly by platinum in 

 the form of the so-called Platinum black. A 

 mixture of oxygen and hydrogen immediately 

 explodes when it is brought in contact with 

 platinum black. Common coal gas inflames when 

 brought in contact with finely divided platinum. 

 Sulphur dioxide is by the same agency quickly 

 oxidised to sulphuric acid. Hydroperoxide is 

 rapidly split into oxygen and water when in 

 contact with platinum black. In all these cases 

 the quantity of platinum black is not diminished 

 after the reaction, and the products of the reactions 

 are never any of the platinum compounds. Similar 

 effects were later on known from sulphuric acid 

 in its influence on the formation of ethyl ether 

 or sulphuric ether from the common ethyl alcohol. 

 Here, too, no sulphuric compound is formed. 

 Ether is often called Sulphuric Ether for the 

 reason that it is prepared by means of sulphuric 

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