160 MR CONNELL ON THE VOLTAIC DECOMPOSITION OF 



tubes A and C, which were filled with distilled water, A being made negative and 

 C positive by a power of 50 pairs of 2-inch plates, no decided indications of the 

 formation of acid were obtained during an hour's action ; for although, latterly, 

 there was a slight acid reaction at the positive pole, it was not greater than distilled 

 water itself might have yielded, and there was a trace of alkali at the negative. 

 Before, however, deciding conclusively that chloride of gold in solution does not 

 yield to voltaic action, it would be necessary to repeat the experiment with a more 

 powerful current, because it may possibly only be a case of more difficult electric 

 resolution. In such cases, also, atomic constitution may have a considerable, if 

 not the principal, influence on the result. 



Whenever we have obtained an instance of the decided formation of acid in 

 the above circumstances, we may conclude, with every probability, that all haloids 

 of the same nature and atomic constitution, of metals of equal or more powerful 

 affinities, are in the same situation. Thus, having verified the rule for chloride of 

 zinc, we may conclude that all protochlorides of more electro-positive metals, such 

 as manganese, cerium, magnesium, barium, potassium, &c. are dissolved as mu- 

 riates. On the other hand, for the whole series of metals, of less powerful affi- 

 nities, as well as for all haloids of more complex atomic constitution, the matter 

 will still require to be investigated, and I propose to make some further researches 

 on the subject. 



In regard to sal ammoniac, I found that it was resolved into acid and alkali 

 in the above circumstances ; a result shewing that, in solution at least, it is simply 

 muriate of ammonia, and cannot be justly regarded as chloride of ammonium. 



The same reasoning above applied to the results with ordinary haloids, can 

 be readily extended to the hypothetical chloride of ammonium ; and to complete 

 the evidence on this point, I found that a solution of muriate of ammonia yielded 

 the definite quantity of hydrogen from the negative pole. 



The experiments with a positive zinc pole lead to the same result, at least 

 when taken in conjunction with those, shewing that the haloids, if viewed as 

 existing as such in solution, are not directly decomposed. The oxide of zinc, 

 which is dissolved and transferred, must have been taken up by acid which had 

 been previously drawn to the positive side. 



The analogy of the action with a positive zinc pole in alcoholic solutions of 

 haloid salts, as formerly described, leads, by similar reasoning, to the view that, 

 in moderately strong solutions of that description also, such as those of chloride 

 of lithium, iodide of potassium, and moderately saturated alcoholic solutions of 

 chloride of calcium, the haloid decomposes the water of the alcohol, and exists in 

 solution as an oxisalt. Many of the phenomena of the voltaic action on such 

 solutions will thus receive a more ready explanation than on the idea of these 

 salts being dissolved as haloids ; such as the appearance of alkalies and earths at 

 the negative pole, which will thus result directly from the decomposition of a 



