SYNTHETIC CHEMISTRY 



M. Berthelot was able to show that the dif- 

 ference lies simply in the varying amount of en- 

 ergy bound up in the one "form" and the other; 

 hence that the heat evolved by combustion is not 

 the same. A grate -fire of diamonds would be 

 less economical in point of heat effect than a fire 

 of wood-charcoal. Here again was the utility of 

 science made plain! 



A companion puzzle to the allotropes was that 

 of contact, or "catalytic," .action. At ordinary 

 temperatures, oxygen and hydrogen may remain 

 in contact for years; a trace of platinum sponge 

 thrown into the mixture, and there is an explosion 

 violent enough to shatter everything in sight. 

 Oxygen and hydrochloric acid may be heated to a 

 high degree, yet they will not combine. A trace 

 of copper oxide starts a vigorous reaction. Chlorine 

 is avid of metals, yet if both be perfectly dry they 

 may remain in contact for years. A trace of 

 moisture brings an instant change. It all seems 

 as if the catalytic agent, as the third substance is 

 termed, pulls a trigger and sets free the forces of 

 combination, until then locked up. But how this 

 is possible was not in the least clear. 



M. Berthelot took up the problem, and by an 

 ingenious series of experiments disclosed the fact 

 that, for example, in the case of the "catalytic" 

 action of platinum sponge, there was, first, a com- 



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