PEEFACE. 



MY MOTIVE in writing these papers was mainly that 

 which prompted the publication of my Royal Institu- 

 tion lectures ; a desire, namely, to extend sympathy for 

 science beyond the limits of the scientific public. 



The fulfilment of this desire has caused a tempo- 

 rary and sometimes reluctant deflection of thought 

 from the line of original research. But considering 

 the result aimed at, and in part I trust achieved, I do 

 not regret the price paid for it. 



I have carefully looked over all the articles here 

 printed, added a little, omitted a little in fact, tried 

 as far as my time permitted to render the work pre- 

 sentable. Most of the essays are of a purely scien- 

 tific character, and from those which are not, I have 

 endeavored, without veiling my convictions, to exclude 

 every word that could cause needless irritation. 



From America the impulse came which induced me 

 to gather these " Fragments " together, and to my 

 friends in the United States I dedicate them. 



JOHN TYNDALL. 



ATHEN.EUM CLUB : March, 1871. 



