Experimental Researches in Electricity, 355 



was found, after several preliminary arrangements, that a 

 zinc and a platinum wire, each an eighteenth of an inch in 

 diameter, fixed in a support five-sixteenths of an inch apart, 

 and immersed in a solution consisting of one drop of strong 

 sulphuric acid in four ounces of distilled water, and retained 

 in it during eight beats of a watch that gave one hundred 

 and fifty in a minute, produced a deflection of exactly 5| 

 divisions of the scale. Hence then it appeared that a 

 voltaic circuit, consisting of these two small wires was capa- 

 ble of producing in ~th of a minute a current of electri- 

 city equal in deflecting power to that derived from thirty 

 turns of the large machines ; and by extending the experiments 

 to chemical power also, the same standard arrangement was 

 found equivalent to the same number of revolutions of 

 the machine. Hence it follows, that the chemical powers, as 

 well as the magnetic force, is in direct proportion to the abso- 

 lute quantity of electricity which passes. 



The third series terminates here, and we scarcely know 

 which to admire most, the thorough theoretical knowledge 

 of the subject displayed, or the inexhaustible experimental 

 resources, as delicate and beautiful as they are effective, 

 exhibited by Faraday throughout its whole progress. The 

 question of the identity of electricities was in a state of 

 uncertainty, analogous to that of several other questions in 

 physical science, which require the hand of a master to 

 resolve them, and in no instance, in the past history of 

 science, has greater skill or perseverance ever been brought 

 to bear upon such problems, than in that which has now 

 been under consideration. Both in the present and in the 

 succeeding series, there are indications, feeble however and 

 imperfectly developed, of the great principles which were 

 opening on Faraday's mind, and on which he dwells at 

 length in the fifth series of the researches. We seem now 

 to be like travellers drawing gradually nearer and nearer to 

 regions whither silver and gold and precious stones incite 



