182 Prof. Daniell and Dr. Miller on the 



electrolysis of organic compounds, and which we hope to make 

 the subject of future communications, induce us to abstain at 

 present from extending this part of our inquiry to the organic 

 acids. 



4. An inquiry of considerable interest now claims our at- 

 tention, viz. the electrolysis of salts, whose acids, having the 

 same elementary radicle as some of those which have been al- 

 ready examined, are in an inferior degree of oxygenation : 

 such are the arsenites and sulphites. 



(g.) A solution ofarsenite qfpotassa (KO, Asg O3) was care- 

 fully prepared (by dissolving single equivalents of arsenious 

 acid and bicarbonate of potassa in boiling water), and placed 

 in the platinode cell of the diaphragm apparatus; the con- 

 necting cell and the zincode cell were both charged with solu- 

 tion of potassa. During the electrolysis oxygen was given off 

 at the zincode, but an equivalent of hydrogen was not obtained 

 at the platinode, the electrode being covered with metallic 

 arsenic, which was deposited in such abundance as speedily 

 to render the liquid opake ; there was no smell of arseniuretted 

 hydrogen. This diffusion of the metal reduced by secondary 

 action, throughout the solution, contrasts well with the com- 

 pact manner in which metals are deposited, which, like copper 

 from the neutral sulphate, are thrown down by direct voltaic 

 action. The zincode solution was exactly neutralized by acetic 

 acid; after which a yellow precipitate of the arsenite of silver 

 was produced on adding nitrate of silver. 



In this case, as in that of the arseniate just described (3.j^), 

 free oxygen was evolved, but the corresponding hydrogen ari- 

 sing from the secondary action of the potassium at the other 

 electrode was taken up in the reduction of the arsenious acid 

 in contact with which it was evolved. No such reduction of 

 the arsenic acid was effected. 



It might have been anticipated that the oxygen in travelling 

 with the arsenious acid to the zincode would have combined 

 with it, and formed a portion of arsenic acid ; but no such re- 

 sult took place : and it must be remarked, that two equivalents 

 of oxygen instead of one would be required fully to oxidate 

 the whole. We nuist, therefore, conclude that Asg O3 + O 

 constitute what we may for the present distinguish as a sub- 

 oxarsenio7i. 



The experiment was repeated, by charging all the three 

 cells of the apparatus with the solution of the salt, when oxy- 

 gen was given off" from the zincode as before, and arsenious 

 acid was deposited in white crystals. 



{h.) The carbonates and oxalates may be compared together 

 in the same point of view as acids of the same radicle in differ- 



