106 Experimental Researches in Electricitij, 



" Water makes a pole of difficult application except in a few 

 cases, because of its small conducting power, its miscibility 

 with most substances acted upon, and its general relation to 

 them in respect of chemical affinity. It consists of elements 

 which in their electrical and chemical relations are directly 

 and powerfully opposed, yet combining it from a body more 

 neutral in its character than any other. So that there are 

 but few substances which do not come into relation by che- 

 mical affinity with water or one of its elements : and there- 

 fore either water or its elements are transferred, and assist in 

 transferring the infinite variety of bodies which in association 

 with it, can be placed in the course of the electric current. 

 Hence the reason why it so rarely happens that the evolved 

 substances rest at the first surface of the water, and why it 

 therefore does not exhibit the ordinary of a pole. 



"Air, however, and some gases are free from the latter 

 objection, and may be used as poles in many cases, but in 

 consequence of the extremely low degree of conducting power 

 which belongs to them, they cannot be employed with the 

 voltaic apparatus. This limits their use : for a voltaic appa- 

 ratus is the only one yet discovered, which supplies suffici- 

 ent quantity of electricity to effect electro-chemical decom- 

 position with facility." 



We have now finished the analysis of the fifth series of 

 Faraday's researches, and here we purpose bringing our 

 remarks upon the masterly work to a close. Nine series 

 still remains, but to analyse these would require more time 

 and space, than circumstances admit of our devoting to them, 

 and we entertain insuperable objections to commenting on a 

 work of this nature in a superficial or cursory manner. To 

 the volume itself, we would direct all those whose interest 

 may have been excited, and we can safely assure them of 

 one of the richest of intellectual treats, and a series of new 

 ideas developed with striking perspicuity in a style, chaste, 

 philosophical, and singularly attractive. 



