ofAqueoits and Alcoholic Solntmis. 245 



periment may evidently be extended to sulphuric, phosphoric 

 and other oxyacids. 



This result may be further illustrated on the principle of 

 the voltameter, A current of the same power as above was 

 passed through a solution of iodic acid, and one of sulphuric 

 acid diluted with twelve parts of water. Iodine without any 

 elastic fluid separated from the negative pole of the iodic so- 

 lution, and from the other poles the following quantities of 

 gas were collected. 



Negative of sulphuric solution '33 cubic inch. 

 Positive of do. do. '12 „ 



Positive of iodic solution '14 ,, 



This result can scarcely be explained except on the idea 

 of the direct decomposition of water only; for similar quan- 

 tities of oxygen were liberated from both solutions, notwith- 

 standing the difference of atomic constitution of the two acids ; 

 and whilst a corresponding quantity of hydrogen was evolved 

 from the sulphuric solution, that from the iodic did not ap- 

 pear, and was plainly occupied in reducing iodine. 



In like manner when the same current was passed through 

 dilute sulphuric acid and a solution of boracic acid, it was 

 found that very nearly the same relative quantities of oxygen 

 and hydrogen were evolved from both solutions in the same 

 time, notwithstanding the difference in the atomic constitution 

 of the two acids. There was therefoi'e little doubt that in 

 both solutions the water and not the acid had suffered decom- 

 position. 



"We turn now to the hydracids. When a solution of mu- 

 riatic or hydriodic acid, not too weak, is acted on under or- 

 dinary circumstances, there is an immediate liberation of 

 chlorine or iodine without oxygen at the positive pole, and of 

 hydrogen at the negative. The first view which strikes one, 

 is that the hydracid is directly resolved into its elements ; and 

 this is the view which Mr. Faraday has adopted. It is not, 

 however, difficult to show that the decomposition is a secondary 

 one. A moderately strong solution of muriatic acid was 

 placed in the tube A, fig. 1, and distilled water in B, the con- 

 necting asbestus being moistened with the latter fluid, A be- 

 ing made negative, and B positive by a power of fifty pairs of 

 two-inch plates. There was speedy effervescence from both 

 poles, and in about a quarter of an hour a trace of acid was 

 found in the positive tube, which went on increasing ; but it 

 was not until after nine hours' action that a feeble and doubtful 

 odour of chlorine could be detected in that tube. When the 

 conducting power of the water in B was improved by adding' 

 a few drops of sulphuric acid, a brisker effervescence than 



