2 IMr. G. Gore on the Development of Dynamic Electricity 



electricity is generated, and therefore, in order to obtain an 

 answer to the first of the questions, I made similar experiments 

 with liquids. I took two Florence flasks (fig. 1), one of 3^ 

 inches diameter, and the other of 3| inches ; the smaller one 

 was cut off evenly at its middle at an angle of about 40 degrees 

 to its largest diameter, and the largest end of the funnel so ob- 

 tained was accurately closed by a porous earthenware diaphragm 

 ~th of an inch thick, ce- 

 mented in with marine 

 glue ; the neck was also 

 cut ofi", and a bent glass 

 tube attached in its place 

 by means of a short piece 

 of vulcanized india-rubber, 

 A, to prevent the heated 

 liquid ascending against 

 the upper wire : the larger 

 one was also cut oiF at its 

 middle in a similar man- 

 ner. The small end of each 

 of these funnels was closed by a cork, with a piece of slender 

 copper wire projecting about half an inch inside. The larger 

 flask was fixed on a stand in an inclined position with its small 

 end downwards, as in the figure, and was nearly filled with a 

 solution composed of 220 grains of sulphate of copper and 10 

 ounces of distilled w^ater; the smaller one was then perfectly 

 filled with a portion of the same liquid and its upper end closed" 

 by its cork, and the outer ends of the wires connected with a 

 suitable galvanometer. On bringing the wet porous base of the 

 upper flask suddenly in contact with the liquid of the lower ves- 

 sel, no perceptible electric cun-ent was developed by chemical or 

 other difl"erences in the projecting ends of wire. The upper end 

 of the lower liquid was now heated to nearly its boiling-point by 

 means of a small spirit-lamp, and the whole surface of the porous 

 diaphragm then suddenly immersed in it to about one-eighth of 

 an inch deep : no deflection of the galvanometer needles took 

 place. I repeated this experiment several times with the same 

 result. I also made the same kind of experiment with glass vessels 

 5f inches in diameter, with bent upper tube, porous earthenware 

 diaphragm yV^ ^^ ^^ ^^^^ thick, and the same liquid, but still 

 obtained no cm-rent with the upper end of the lower column at 

 212° F. 



4. To ascertain whether the questioned effect was neutralized 

 or prevented by atmospheric air dissolved in the liquid, or by 

 any opposing cjuality of the diaphragm, I tried again with the 

 liquid pre-boiled, and with a prepared ox-bladder diaphragm 5| 



