'2-26 On some Chemical Agencies of Electricity. 



connecting fluid is water free from air*; for this substance 

 does not readily undergo chemical change, and the equili- 

 brium seems to be capable of being permanently restored 

 through it. Concentrated sulphuric acid, which is a much 

 more perfect conductor, is equally inefficient, for it has lit- 

 tle action upon zinc, and is itself decomposed only by a 

 very strong power. Piles, containing as their fluid element 

 cither pure water or sulphuric acid, will undoubtedly give 

 single shocks, and this efl"ect is connected with the restora- 

 tion of the equilibrium disturbed by tlic energies of the me- 

 tals; but when their extreme plates are connected there is no 

 exhibition, as in usual cases of electromotion. Water con- 

 taining loosely combined oxvgen is more efficient than 

 water containing cnnnnon air, a? it enables oxide of 

 zinc to be formed more rapidly, and in larger quantities, 

 Neutrosaline solutions which are at first very active, lose 

 thiCir energy in proportion as their acid arranges itself on the 

 side of the 7,inc, and their alkali on that of the copper ; 

 and I have found the powers of a combination nearly de- 

 stroyed from this cause verv much revived, merely by agi- 

 tating the fluids in the cells and mixing their parts together. 

 Diluted acids, which are themselves easily decomposed, or 

 uhich assist the decomposition of wa.ter, are above all other 

 substances powerful ; for they dissolve the zinc, and furnish 

 only a gaseous product to the negative surface^ which is im- 

 mediatelv di>engased. 



There arc other experiments connected with very striking 

 results, wliich offer additional reasons for supposing the de- 

 composition of the chemical menstrua essential to the con- 

 tinued electromotion in the pile. 



As when an electrical discharge is produced by means of 

 small metallic surfaces in the Voltaic batterv, (the opposite 

 Slates being exalted,) sensiiile heat is the consequence, it 

 occurred to me, that if the decomposition of the cheniical 

 ai^ents was essential to the balance of the opposed electrici- 

 ties, the effect, in a saline solution, of this decomposition, 



* The experiments proving; this fact, and the other analogous facts in this 

 jjujc, may be seen detailed in Nicholson's Journal, 'Ito. vol. iv. page 33S and 

 303 ; and Thil. Mag. vol. x. page 40. 



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