86 Mr. Binks on the Laws of Action of Voltaic Electricity, 



controverted points in the laws of this science ; and one of 

 such to which I shall attempt to apply it will be to determine 

 the real relation that subsists between the deflexions of the 

 magnetic needle and the quantity of zinc expended in pro- 

 ducing those deflexions, or, which is the same thing, between 

 the deflexions and the quantity of electricity which produces 

 them. 



Fourth Investigation, 

 Up to this step in the inquiry I have restricted myself to 

 the use of diluted sulphuric acid as the exciting agent. The 

 foregoing facts, or, it may be, laws of action, have therefore 

 been determined for this one condition only out of the many 

 under which the electrical action may be developed. The 

 phenomena attendant upon this mode of excitation are, pri- 

 marily, the decomposition of the water, the combination of its 

 oxygen with the zinc, and the liberation of its hydrogen as 

 hydrogen, that is, in its gaseous state, upon the surface of the 

 conducting metal. Now, in the results of the first investiga- 

 tion we perceive that there exists a coincidence between the 

 relative bulks (compared with equal weights) of oxygen and 

 hydrogen gases and the relative surfaces of the two metallic 

 plates ot any voltaic circle in which the maximum electrical 

 effect takes place. This fact, which I speak of as a mere co- 

 incidence, should not be overlooked. It may indicate a priori 

 that the same relative proportions in the two metals which 

 have been determined for this one instance may be needed in 

 every instance in which water is decomposed and its hydrogen 

 liberated in the form of gas. But we have no reason to anti- 

 cipate a priori that if any other substance than hydrogen be 

 yielded at the conducting plate, we shall still, to produce the 

 maximum effect, have to preserve the same proportions of the 

 two metals as have been determined for that case. Suppose the 

 operations within the cells of any battery to be so modified that, 

 although water shall still be the substance decomposed, yet 

 intead of the production of hydrogen we have the deposition 

 of metallic copper, or the reformation of water, or the forma- 

 tion of some other body physically different from hydrogen 

 as the results of the operations, what proportions of the two 

 metals will then be needed to ensure the maximum effect? 

 Such modifying agents are readily obtained. A proper mix- 

 ture of the nitric and sulphuric acids with water will lead, not 

 to the production of gaseous hydrogen, but to the formation 

 of water and ammonia within the cells of the battery ; and the 

 solution of sulphate of copper to the deposition of metallic 

 copper and the reformation of water. I will at this time exa- 

 mine but the latter of these two, and endeavour to determine 



