The Tendencies of Chemistry 



the volatility of the carbonic-acid gas is actually 

 the determining cause of the reaction. But 

 now we are dealing with experiments and not 

 with hypotheses, and these experiments actually 

 show us a state of equilibrium capable of being 

 upset in either direction; and the sign=, which 

 in the old chemical equation expressed solely 

 the conservation of the masses in the reaction, 



CaC0 3 =CaO + C0 2 



assumes henceforth a new and more striking 

 meaning; it indicates the equilibrium of opposing 

 forces. 



We should now understand why chemistry 

 owes so much to the study of these states of 

 equilibrium, and of these reactions which can 

 take place either in one direction or in the 

 other, and which are called reversible reactions; 

 it is because in every science a knowledge of 

 statics precedes and facilitates the knowledge 

 of dynamics. When we witness one of these 

 reactions which attract our attention by their 

 violence, such as the attack of zinc by sulphuric 

 acid, we can only note the phenomenon, but are 

 incapable of causing it to alter its course; now 

 it is only by methodical experiment that scien- 



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