1 2 IMMUNO-CATALYSIS 



tion of heat energy; or, (b) through chemical affinities; or, (c) the 

 apphcation of force to non-spontaneous processes. This force may be 

 electromotive, as in electrolytic processes; or, (d) by the accelerating 

 effect of organic or inorganic catalysts. Two important facts are to be 

 observed. In the first place, we note that the final products either 

 contain the parts of the reactants, or are derived from a single 

 substance, or a single complex molecule is formed out of two or more 

 reactants. In contrast, the enzyme, or organic and inorganic catalysts 

 do not enter into any irreversible union with any of the reaction 

 products. 



The Synthesis of Sul'phuric Acid hy the Catalytic Contact Process. 

 In this process the interaction of sulphur dioxide and oxygen is the 

 principal reaction. The interaction between the two main reactants 

 can be hastened by the catalytic surfaces of porcelain, ferric oxide, and, 

 more especially, by finely divided platinum spread in a fine grey 

 powder on the fibers of asbestos to obtain maximum active surface. 

 Under controlled temperature conditions the above gases are blown 

 over the catalytic system forming sulphur trioxide. The platinum re- 

 mains unchanged and functions continuously so long as arsenious 

 oxide and other impurities do not poison the active surface of the 

 catalyst. 



The surface of the finely divided platinum is characterized by 

 strong adsorbing powers. It holds the gaseous molecules with relative 

 firmness, and it is believed that there the molecules undergo activation 

 prior to a chemical union. Once this has taken place the active surface 

 is set free to function again. 



The Synthesis of Sulphuric Acid in a Homogeneous Catalytic 

 System— Chamber Process.— Water vapor, sulphur dioxide, nitrous 

 anhydride (N2O3), and oxygen participate in the synthesis of sul- 

 phuric acid in this process. When these gases are thoroughly mixed in 

 large leaden chambers it is assumed probably that the greater part of 

 the acid is formed by the following two successive actions (Rideal and 

 Taylor, 1926): 



O— NO 



1 . H.,0 -f 2SO^ -f N0O3 + O, -> 2SO^ Nitrosylsulphuric acid 



OH 



