EPOCH OF DAVY AND FARADAY. 291 



of simple substances and their compounds are as whole numbers.* 

 MM. Kopp, Playfair, and Joule have labored in the same field.] 



I cannot now attempt to trace other bearings and developments of 

 this remarkable discovery. I hasten on to the last generalization of 

 chemistry ; which presents to us chemical forces under a new aspect, 

 and brings us back to the point from which we departed in commenc- 

 ing the history of this science. 



CHAPTER IX. 

 EPOCH OF DAVY AND FARADAY. 



Sect. i. Promulgation of the Electro-chemical Theory by Davy. 



THE reader will recollect that the History of Chemistry, though 

 highly important and instructive in itself, has been an interruption 

 of the History of Electro-dynamic Research : a necessary interrup- 

 tion, however ; for till we became acquainted with Chemistry in 

 general, we could not follow the course of Electro-chemistry : we 

 could not estimate its vast yet philosophical theories, nor even express 

 its simplest facts. We have now to endeavor 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 delicacy. We cannot 

 execute it at all, except we suppose that the great truths, of which the 

 discovery marks this epoch, have already assumed their definite 

 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 

 guesses only when we have gained our point and guessed rightly. We 

 might personify philosophical theories, and might represent them to 

 ourselves as figures, all pressing eagerly onwards in the same direc- 



9 Die molecular-volume der Chemischen Verbiiidungen infexten und fllissingen 

 Zustande, 1843. 



