192 HISTORY OF CHEMISTRY. 



the subject, notice one or two of the remarkable 

 .subordinate features of Faraday's discoveries. 



Sect. 3. Consequences of Faraday s Discoveries. 



FAB AD AY'S volta-electrometer, in conjunction with 

 the method he had already employed, as we have 

 seen, for the comparison of voltaic and common 

 electricity, enabled him to measure the actual quan- 

 tity of electricity which is exhibited, in given cases, 

 in the form of chemical affinity. His results ap- 

 peared in numbers of that enormous amount which 

 so often comes before us in the expression of natural 

 laws. One grain of water 40 will require for 'its de- 

 composition as much electricity as would make a 

 powerful flash of lightning. By further calculation, 

 he fiiids this quantity to be not less than 800,000 

 charges of his Leyden battery 41 ; and this is, by his 

 theory of the identity of the combining with the 

 decomposing force, the quantity of electricity which 

 is naturally associated with the elements of the 

 grain of water, endowing them with their mutual 

 affinity. 



Many of the subordinate facts and laws which 

 were brought to light by these researches, clearly 

 point to generalizations, not included in that which 

 we have had to consider, and not yet discovered: 

 such laws do not properly belong to our main plan, 

 which is to make our way up to the generalizations. 

 40 Art. 153. 41 861. 



