338 Mr. Faraday's Reply to Dr. John Davy's Remarks. 



fessor Jameson, the learned Editor of the Edinburgh Journal, 

 may be to act impartially, and give me the same opportunity of 

 publication he has given Dr. Davy, he cannot do so before the 

 lapse of three months. Under these circumstances, and with 

 the old adage before my eyes that "delays are dangerous," may 

 I beg you to insert this letter and my paper in the next Num- 

 ber of the Philosophical Magazine ? and I may still, perhaps, 

 be indebted to the kindness of Professor Jameson for its in- 

 sertion in the next number of the Journal in which Dr. Davy's 

 " Remarks" have appeared. 



I am, my dear Sir, most truly yours, 

 Royal Institution, Oct. 10, 1835. M. Fa RAD AY. 



The secretary of the Royal Society having mentioned to 

 me the preceding paper, I requested a sight of it, that I might 

 as soon as possible correct any error in the papers to which 

 it referred, and of which it might make me conscious; and 

 having read it, I am induced to hope the present note may 

 accompany Dr. Davy's observations. 



I do not know that I have any right to suppose Dr. Davy 

 generally does not understand me in my papers, and yet some- 

 thing of this kind must have occurred; for instance, the new 

 law of conduction referred to in my Fourth Series* is not even 

 now evident to him, and therefore I think I cannot have 

 erred in supposing Sir Humphry Davy unacquainted with it. 

 The law is, that all substances decomposable by the pile are in 

 the fluid state conductors, and in the solid state nonconductors, 

 of the electricity of the voltaic battery (393. 394. 404. 407. 

 413. 505. 676. 679. 697., &c.f). The more careful examina- 

 tion of this law in other parts of my printed Researches shows 

 that no bodies but electrolytes have this relation to heat and 

 electricity, the few exceptions which seem to occur being 

 probably only apparent (690. &c.f ). That the title of law, 

 therefore, is merited, and that this law was not known to Sir 

 Humphry Davy, are, I think, justifiable conclusions, notwith- 

 standing Dr. Davy's remarks. As to Priestley's results with 

 the electric machine, they really have nothing to do with the 

 matter. 



I have said that Sir Humphry Davy spoke in general terms. 

 " The mode of action by which the effects take place is stated 

 very generally, so generally indeed that probably a dozen 

 precise schemes of electro-chemical action might be drawn up 

 differing essentially from each other, yet all agreeing with the 



[• An abstract of Mr. Faraday's Fourth Series will be found in Lond. 

 and Edinb. Phil. Mag., vol. iii. pp. 449, 450.— Edit.] 



[f The paragraphs here referred to belong to Mr. Faraday's Seventh 

 Series, and will be found reprinted in Lond. and Edinb. Phil. Mag., vol. v. 

 p. 166— 169.-Edit.] 



