182 CORRELATION OF PHYSICAL FORCES. 



placed at different stations remained fixed after the connection 

 with the battery was made, and while the electric current 

 acted by induction on surrounding conducting matter, separa- 

 ted from the wires by their gutta percha coating, so that a 

 sort of Leyden phial was formed ; but as soon as this induc- 

 tion had produced its effect between each station, or, so to 

 speak, the phial was charged, the needles successively were 

 deflected : it is like the case of a pulley and weight, which lat- 

 ter exhausts force while it is being raised ; but when raised, 

 the force is free, and may be used for other purposes. 



If a battery of one cell, just capable of decomposing water 

 and no more, be employed, this will cease to decompose while 

 making a magnet. There must, in every case, be prepon- 

 derating chemical affinity in the battery cells, either by the 

 nature of its elements or by the reduplication of series, to 

 effect decomposition in the voltameter ; and if the point is 

 just reached at which this is effected, and the power is then 

 reduced by any resistance, decomposition ceases: were it 

 otherwise, were the decomposition in the voltameter the 

 exponent of the entire force of the generating cells, and these 

 could independently produce magnetic force, this latter 

 force would be got from nothing, and perpetual motion be 

 obtained. 



To take another and different example : A piece of zinc 

 dissolved in dilute sulphuric acid gives somewhat less heat than 

 when the zinc has a wire of platinum attached to it, and is 

 dissolved by the same quantity of acid. The argument is 

 deduced that, as there is more electricity in the second than 

 in the first case, there should be less heat ; but as, according 

 to our received theories, the heat is a product of the electric 

 current, and in consequence of the impurity of zinc electrici- 

 ty is generated in the first case molecularly, in what is called 

 local action, though not thrown into a general direction, 

 there should be more of both heat and electricity in the sec- 

 ond than in the first case, as the heat and electricity due to 



