470 Notices respecting New Books. 



we think it desirable to cite, both in justice to the author, and on 

 account of their intrinsic interest ; — 



" The readers of the vohime will, I hope, do me the justice to remember 

 that it was not written as a ivhole, but in parts; the earlier portions rareljf 

 having any known relation at the time to those which might follow. If I 

 had rewritten the work, I perhaps might have considerably varied the form, 

 but should not have altered much of the real matter : it would not, however, 

 then have been considered a feithful reprint or statement of the course and 

 results of the whole investigation, which only I desired to supply. 



" I may be allowed to express my great satisfaction at finding that the 

 different parts, written at intervals during seven years, harmonize so well 

 as they do. There would have been nothing particular in this, if the parts 

 had related only to matters well ascertained before any of them were writ- 

 ten : — but as each professes to contain something of original discovery, or 

 of correction of received views, it does surprise even my partiality, that they 

 should have the degree of consistency and apparent general accuracywhich 

 they seem to me to present. 



" I have made some alterations in the text, but they have been altogether 

 of a typographical or grammatical character; and even where greatest, 

 have been intended to explain the sense, not to alter it. I have often added 

 Notes at the bottom of a page, for the correction of errors, and also the 

 purpose of illustration : but these are all distinguished from the Original 

 Notes of the Researches by the date oi Dec. 1838. 



" The date of a scientific paper containing any pretensions to discovery 

 is frequently a matter of serious importance, and it is a great misfortune 

 that there are many most valuable communications, essential to the history 

 and progress of science, with respect to which this point cannot now be as- 

 certained. This arises from the circumstance of the papers having no dates 

 attached to them individually, and of the journals in which they appear 

 having such as are inaccurate, i. e. dates of a period earlier than that of 

 publication. I may refer to the note at the end of the First Series, as an 

 illustration of the kind of confusion thus produced. These circumstances 

 have induced me to affix a date at the top of every other page, and I have 

 thought myself justified in using that placed by the Secretary of the Royal 

 Society on each paper as it was received. An author has no right, perhaps, 

 to claim an earlier one, unless it has received confirmation by some public 

 act or officer." 



In connexion with the general subject of the volume, Mr. Faraday 

 then alludes to his papers on Electro-magnetic Rotations in the 

 Quarterly Journal of Science for 1822, and on Magneto-electric 

 Induction in the Annales de Chimie, vol. li., which, he remarks, 

 " might, as to the matter, very properly have appeared in this volume, 

 but they would have interfered with it as a simple reprint of the 

 ' Experimental Researches' of the Philosophical Transactions." He 

 next refers in relation to the Fourth Series of his own Researches, 

 on a nev/ law of electric conduction, to Franklin's experiments on 

 the non-conduction of ice as brought forward by Professor Bache, 



observing, "These, though they in no way anticipate the 



expression of the law I state as to the general effect of liquefaction 

 on electrolytes, still should never be forgotten when speaking of 

 that law as applicable to the case of water." 



" There are two papers which I am anxious to refer to, as corrections or 

 criticisms of parts of the Experimental Researches. The first of these is 



