333 ON lOMX CHEMICAI, AGENCIES OF EtECTftlClTr^ 



Axjtlon of else- Sulphate of barytes^ as might be supposed, proTed much 

 •raiposingcom- ''^^■'® ^*®<^"^* ^^ decomposition than either sulphate of 

 jdunds. strontites oi^ fluate of lime. I had made four or five ex- 



periments upon it, Avith the same kind of apparatus that 

 had been applied to the fluate of lime, befpre i was able to 

 gain decided results. In the last process pcrfoi*med on thi^ 

 substance, two pieces of a large single crystal were hol- 

 lowed by grinding, so as to contain about five grains of 

 water each ; they were connected by moist asbestusj and 

 constantly subjected during four days to the strong aciion 

 of a battery of 150 pairs of plates of 4 inches square. As 

 the water diminished, its place was wipplied by new qtian^ 

 tities. At the conclusion of the experiment the fluid on the 

 i>ositive side of the apparatus instantly reddened IHmusj 

 tasted Tcry sour, and gave a distinct precipitate with a so- 

 lution of muriate of barytes; the water on tke other side 

 deepened the tincture of turmeric; but did not render so- 

 lution of sulphate of potash turbid. There was a small 

 quantity of white crust, however, on the sides and tha 

 bottom of the cavity, and I conceived that this might be 

 the barytes, which, during the extremely slow decompo* 

 sition, would have combined with the carbonic acid of the 

 atmosphere. To ascertain if this had been the case, I in- 

 troduced into the cavity a drop of diluted muriatic acid ; 

 a slight effervescence appeared, and the fluid obtained occa« 

 , sioned a distinct white cloudiness in solution of sulphate of 

 soda. 



In all these cases the constituent parts of the bodies 

 newly arranged by the effects of electricity existed in con- 

 siderable quantities, and exposed on a latge surfitce to its 

 action, I had great reason to believe, from the trials M'ith 

 distilled water in different vessels, that very minute portions 

 of acid and alkaline matter might be disengaged by this 

 agency from solid combinations, principally consisting of 

 pure earths. 



This part of the investigation was easily elucidated. 



For a purpose of geological inquiry, which on a future 



occasion I shall have the honour of laying before the 



Society, I had made a careful analysis of a specimen of 



fine grained basalt from Port Rush in the county of Antrim, 



