On some Chemical Agencies of Elccirldhj. 109 



stances, readily through muriatic and nitric acids ; and, vice 

 i^ersd, these acids passed w ith facility through aqueous solu- 

 tions of barytes and strontites : hut in experiments in which 

 it was attempted to pass sulphuric acid through the sarae 

 menstrua, or to pass barytes or strontiles through this acid, 

 the resiihs were very ditR-rent. 



When soiiilion of sulphate of potash was in the neo-ative 

 part of the circuit, distilled water in the positive part, and 

 saturated solution of barytes in the middle, no sensible quan- 

 tity of sulphuric acid existed in the disiilltd water after thirtv 

 hours, the power of 150 being used : after four days, sul- 

 phuric acid appeared, but the quantity wa,3 cxtremelv mi- 

 nute: much sulphate of barytes had formed in tiie inter- 

 mediate vessel; the solution of barytes was so weak as barely 

 to tinge litmus ; and a thick film of carbonate of barytes liad 

 formed on the surface of the fluid. With solution of stron- 

 tites the result was very analogous, but the sulphuric acid 

 was sensible in three davs. 



When solution of muriate of barytes was made positive 

 by the power of 150, concentrated sulphuric acid interme- 

 diate, and distilled water negative, no barytes aj^peared in 

 the distilled water when the experiment had been carried on 

 for four days ; but much oxymnriatic acid had formed in the 

 positive vessel, and nuich sulphate of barytes had been de- 

 posited in the sulj)huric acid. 



Such of the metallic oxides as were made subjects of ex- 

 periment passed through acid solutions from the positive ta 

 the negative side, but the eflect was much longer in taking 

 place than in the instances of the transition of alkaline mat- 

 ter. When solution of green sulphate of iron was made 

 positive, solution of nuiriatic acid intermediate, and water 

 negative, in the usual arrangement, green oxide of iron be- 

 gan t<i appear in about ten hours upon the nceative coa- 

 necting amianthus, and in three days a consirlerable portLin 

 had been deposited in the tube. Analogous results w'.>re 

 ol)tained with sulphate of copper, nitrate of lead, and nitru- 

 muriate of tin. 



I made several experiments on the transition of alkaline 



and 



