34? Dr. Faraday's Experimental Researches in Electricity, 



of a horn, are often heard only in their upper octave. This 

 singular foot I presume to depend on the greater strength of 

 the moderately rapid vibrations, by which they are enabled 

 to traverse a longer space than the fundamental note. The 

 same thing occurs with distant echoes ; and, although natural 

 philosophers have not noticed this circumstance, melodrama- 

 tists have successfully availed themselves of it to represent 

 the effect of an echo on the stage. So also Shakspeare : 



** Babbling echo mocks the hounds, 



Replying shrilly to the well tuned horns." 



Again, 



" Thy hounds shall make the welkin answer them, 

 And fetch shrill echoes from their hollow earth.' 



Half-moon Street, Nov. 13, 1834. 



V. Experimental Researches in Electricity. — Eighth Series, 

 By Michael Faraday, D.C.L.F,R.S.FullerianProf, Chem-. 

 Royal Institution,^ Corr. Memb. Royal and Imp» Acadd. of 

 Sciences, Paris, Petershurgh, Florence, Copenhagen, Berlin, 



^. 14«. On the Electricity of the Voltaic Pile; its source, 

 quantity, intensity, and general characters, f i. Oil 

 simple Voltaic Circles. 51 ii» On the intensity neces- 

 sary for Electrolyzation. % m. On associated Voltaic 

 Circles, or the Voltaic Battery, f iv. On the resist^ 

 ance of an Electrolyte to Electrolytic action. % v. Ge^ 

 neral remarks on the active Voltaic Battery. 



f i. On simple Voltaic Circles. 



875. T^HE great question of the source of electricity in the 

 -■- voltaic pile has engaged the attention of so many 

 eminent philosophers, that a man of liberal mind and able to 

 appreciate their powers would probably conclude, although he 

 might not have studied the question, that the truth was some- 

 where revealed. But if in pursuance of this impression he 

 were induced to enter upon the work of collating results and 

 conclusions, he would find such contradictory evidence, such 

 equilibrium of opinion, such variation and combination of 

 theory, as would leave him in complete doubt respecting what 

 he should accept as the true interpretation of nature: he 

 would be forced to take upon himself the labour of repeating 



* From the Philosophical Transactions for 1834. Part II. p. 425. This 

 paper was received by the Royal Society April 7th, and read June 5th, 1834. 



