PUBLISHEKS' NOTE. 



THB first edition of Prof. Tyndall's " Fragments of 

 Science " was published some twenty years ago as a sin- 

 gle volume, which was made up of a score or more of 

 his detached essays, addresses, and reviews. The book 

 was afterward revised, some of the papers recast, and 

 from time to time new ones added, until, the size of the 

 work becoming somewhat unwieldy, the present two- 

 volume edition was decided upon. This contains fif- 

 teen additional papers, and represents the author's 

 latest changes and revisions. The volumes are uniform 

 with " New Fragments," recently issued, and the three 

 together include all the occasional writings which 

 their author has decided to preserve in permanent 

 form. 



2022122 



