CONCLUDING REMARKS. 181 



so were the matter in a suitable condition for their develope- 

 ment, or our means of detecting them sufficiently delicate. 



This simultaneous production of several different forces 

 seems at first sight to be irreconcileable with their mutual and 

 necessary dependence, and it certainly presents a formidable 

 experimental difficulty in the way of establishing their equiv- 

 alent relations ; but when examined closely, it is not in fact 

 inconsistent with the views we have been considering, but is 

 indeed a strong argument in favour of the theory which re- 

 gards them as modes of motion. 



Let us select one or two cases in which this form of ob- 

 jection may be prominently put forward. A voltaic battery 

 decomposing water in a voltameter, while the same current 

 is employed at the same time to make an electro-magnet, 

 gives nevertheless in the voltameter an equivalent of gas, or 

 decomposes an equivalent of an electrolyte for each equiva- 

 lent of chemical decomposition in the battery cells, and will 

 give the same ratios if the electro-magnet be removed. " Here, 

 at first sight, it would appear that the magnetism was an ex- 

 tra force produced, and that thus more than the equivalent 

 power was obtained from the battery. In answer to this 

 objection it may be said, that in the circumstances under 

 which this experiment is ordinarily performed, several cells 

 of the battery are used, and so there is a far greater amount 

 of force generated in the cells than is indicated by the effect 

 in the voltameter. If, moreover, the magnet be not inter- 

 posed, still the magnetic force is equally existent throughout 

 the whole current ; for instance, the wires joining the plates 

 will attract iron filings, deflect magnetic needles, &c., and 

 produce diamagnetic effects on surrounding matter. By the 

 iron core a small portion of the force is, indeed, absorbed 

 while it is being made a magnet, but this ceases to be ab- 

 sorbed when the magnet is made ; this has been proved by 

 the observation of Mr. Latiiner Clarke, who has found that 

 along the wires of the electric telegraph the magnetic needles 



