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CHAPTER IX. 

 EPOCH OF DAVY AND FARADAY. 



Sect. 1. Promulgation of the Electro-chemical 

 Theory by Davy. 



THE reader will recollect that the History of 

 Chemistry, though highly important and in- 

 structive in itself, has been an interruption (p. 112) 

 of the History of Electro-dynamic Research : a 

 necessary interruption, however; for till we became 

 acquainted with chemistry in general, we could not 

 follow the facts of electro-chemistry : we could not 

 estimate its vast yet philosophical theories, nor even 

 express its simplest facts. We have now to endea- 

 vour to show what has thus been done, and by what 

 steps ; to give a fitting view of the Epoch of Davy 

 and Faraday. 



This is, doubtless, a task of difficulty and deli- 

 cacy. We cannot execute it at all, except we sup- 

 pose that the great truths, of which the discovery 

 marks this epoch, have already assumed their defi- 

 nite and permanent form. For we do not learn the 

 just value and right place of imperfect attempts and 

 partial advances in science, except by seeing to what 

 they lead. We judge properly of our trials and 



