Ofi some Cliemical Agencies of Electricity. 227 



and of the transfer of the alkaU to the negative side, and of 

 the acid to the positive side, ought, under favourable cir- 

 cumstances, to be connected with an increase of tempera- 

 ture. 



I placed the gold cones, which have been so often men- 

 tioned, in the circuit of the battery with the power of 100> 

 I filled them with distilled water, and connected them by a 

 piece of moistened asbcstus, about an inch in length and i of 

 an inch diameter ; I provided a small air-thermometer ca- 

 pable of being immersed in the gold cones, expecting (if 

 anv) only a very slight change of temperature ; I introduced 

 a drop of solution of sulphate of potash into the positive 

 cone : the decomposition instantly began : potash passed 

 rapidly over into the negative cone, heat was immediately 

 sensible ; and in less than two minutes the water was in a 

 state of ebullition. 



I tried the same thing with a solution of nitrate of am- 

 monia, and in this instance the heat rose to such an inten- 

 sity as to evaporate all the water in three or four minutes, 

 with a kind of explosive noise ; and at last actual inflamma- 

 tion took place, with the decomposition and dissipation of 

 the greatest part of the salt*. 



That the increase of the conducting power of the water 

 by the drop of saline solution had little or nothing to do 

 with the effect, is evident from this circumstance. I intro- 

 duced a quantity of strong lixivium of potash into the cones, 

 and likewise concentrated sulphuric acid, separately, which 

 are better conductors than solutions of the neutral salts ; 

 but there was very little sensible effect. 



The same principles will apply to all the varieties of the 

 electrical apparatus, whether containing double or single 

 plates; and if the ideas developed in the preceding sections 

 be correct, one property operating under different modifica- 

 tions is the universal cause of their activity. 



* la this process ammonia was rapidly given off froni the surface of the 

 ncgTitive cone, aixl nilruus acid from that of t)ic positive cone, and a wliite 

 vapour was pajduc^ed hy their combination in the atmosphere above the ap- 

 paratus, 



P 2 X. Oil 



