THE ORIGIN OF MOTIVE POWER, 429 



the chemical combinations taking place in a gal- 

 vanic battery may be directed to produce a large, 

 probably in some forms of battery an unlimited, 

 proportion of their heat, not in the locality of 

 combination, but in a metallic wire at any distance 

 from that locality ; or that they may be directed 

 not to generate that part of their heat at all, but 

 instead to raise weights, by means of a rotating 

 engine driven by the current. Thus if we allow 

 zinc to combine with oxygen by the beautiful 

 process which Grove has given in his battery, we 

 find developed in a wire connecting the two poles 

 the heat which would have appeared directly if 

 the zinc had been burned in oxygen gas ; or if 

 we make the current drive a galvanic engine, we 



tion (Cork), August 1843, and published Phil. Mag. October, 

 1843. 



" On the Intermittent Character of the Voltaic Current in 

 certain cases of Electrolysis, and on the Intensity of various 

 Voltaic arrangements." Phil. Mag. February, 1844. 



"On the Mechanical Powers of Electro- Magnetism, Steam, and 

 Horses." By Joule and Scoresby. Phil. Mag. June, 1846. 



"On the Heat disengaged in Chemical Combination." Phil. 

 Mag-. June 1852. 



"On the Economical Production of Mechanical Effect from 

 Chemical Forces. "/W. Mag. Jan. 1853. 



All these articles are republished in vol. i. of Joule's Collected 

 Papers. 



