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cups, and electrified, the decomposition was more rapid. A solution 

 of sulphate of potash being put into each of the cups, and electrified 

 by means of fifty pair of plates for four hours, the acid was found by 

 itself in the positive cup, and the alkaline bases in the negative cup. 

 Similar phenomena took place with sulphate of soda, nitrate of pot- 

 ash, nitrate of barytes, sulphate of ammonia, and alum. When mu- 

 riatic salts were used, these yielded oxymuriatic acid. When com- 

 patible mixtures of neutro-saline compounds were used, the different 

 acids and bases separated in a mixed state, without any regard to 

 their affinities. When solutions of metals, deoxidizable by nascent 

 hydrogen were employed, metallic crystals formed on the negative 

 wire, and some oxide was deposited ; but solutions of iron, zinc, and 

 tin, only deposited oxide ; a great excess of acid was soon observed 

 on the positive side. Although stronger solutions afforded signs of 

 decomposition quicker than weaker ones, yet even the smallest pro- 

 portions seemed to be acted upon with equal energy : as paper tinged 

 with turmeric was immediately rendered brown when plunged into 

 pure water and brought into contact with the negative point ; so 

 paper tinged with litmus was immediately reddened by the positive 

 point, in consequence of the very minute portion of saline matter 

 contained in the paper ; and it further appeared, that in all these 

 decompositions the separation of the constituent parts from the last 

 portions of the compounds was complete when the operation was 

 sufficiently protracted. 



The contact of the solution with the wires was not necessary for 

 its decomposition ; for muriate of potash being put into the middle 

 tube of a series of three, the outer ones containing only water and 

 the wires, alkali soon appeared in that connected with the negative 

 wire, and acid in the other ; and at length they were obtained per- 

 fectly separate. 



In thus causing the acids to be thus transferred from a saline com- 

 pound into water, through moistened amianthus, no change was ob- 

 served to take place in litmus paper placed near the amianthus. The 

 reddening of the litmus paper always took place just above the posi- 

 tive point, and then slowly diffused itself to the middle of the vessel. 

 Similar effects were observed when the alkali was transferred, the 

 turmeric paper first becoming brown close to the negative wire. 



When three glass tubes were used, the two outer tubes holding a 

 solution of muriate of soda, and the middle one sulphate of silver, a 

 communication being made with the central vessel by turmeric paper 

 on the positive side, and by litmus paper on the negative, neither of 

 the papers had its colour changed, although the muriatic acid passing 

 through the amianthus occasioned a dense heavy precipitate in the 

 sulphate of silver, and the soda a more diffuse and lighter one. 



Acid or alkaline substances will also pass through liquids, having 

 a strong attraction for them. In an apparatus of three tubes, Mr. 

 Davy found that sulphuric acid, evolved from sulphate of potash, 

 would pass into water, through either ammonia, lime-water, or weak 

 solutions of potash or of soda. The only effect of strong solutions of 



