Primary and Secondary Results of Electrolyzation. 257 



drogen. When the quantity of products was examined by 

 the volta-electrometer (707. ), the oxygen, whether from 

 strong or weak acid, proved to be in the same proportion as 

 from water. When the acid was diluted to specific gravity 

 1*24, or less, the hydrogen also proved to be the same in 

 quantity as from water. Hence I conclude that the nitric 

 acid does not undergo electro-chemical decomposition, but 

 the water only; that the oxygen at the anode is always a pri- 

 mary result, but that the products at the cathode are often se- 

 condary, and due to the reaction of the hydrogen upon the 

 nitric acid. 



753. Nitre. — A solution of this salt yields very variable re- 

 sults, according as one or other form of tube is used, or as 

 the electrodes are large or small. Sometimes the whole of 

 the hydrogen of the water decomposed may be obtained at the 

 negative electrode ; at other times, only a part of it, because 

 of the ready formation of secondary results. The solution is 

 a very excellent conductor of electricity. 



75i. Nitrate of ammonia, in aqueous solution, gives rise to 

 secondary results very varied and uncertain in their propor- 

 tions. 



755. Sulphurous Acid. — Pure liquid sulphurous acid does 

 not conduct nor suffer decomposition by the voltaic current*, 

 but, when dissolved in water, the solution acquires conducting 

 power, and is decomposed, yielding oxygen at the anode, and 

 hydrogen and sulphur at the cathode. 



756. A solution containing sulphuric acid in addition, was 

 a better conductor. It gave very little gas at either electrode : 

 that at the anode was oxygen, that at the cathode pure hydro- 

 gen. From the cathode also rose a white turbid stream, con- 

 sisting of diffused sulphur, which soon rendered the whole 

 solution milky. The volumes of gases were in no regular 

 proportion to the quantities evolved from water in the volta- 

 electrometer. I conclude that the sulphurous acid was not at 

 all affected by the electric current in any of these cases, and 

 that the water present was the only body electro-chemically 

 decomposed ; that, at the anode, the oxygen from the water 

 converted the sulphurous acid into sulphuric acid, and, at the 

 cathode, the hydrogen electrically evolved decomposed the 

 sulphurous acid, combining with its oxygen, and setting its 

 sulphur free. I conclude that the sulphur at the negative 

 electrode was only a secondary result ; and, in fact, no part of 

 it was found combined with the small portion of hydrogen 



* See also De la Rive, Bibliotheque Universelte, torn. xl. p. 205; or 

 Quarterly Journal of Science, vol. xxvii. p. 407. 



TAird Series. Vol. 5. No. 28. Oct. 1834. 2 L 



