PREFACE. 



The Editor cannot terminate the Third Volume of 

 the Annals of Philosophy without expressing his 

 acknowledgments for the very general and almost 

 unprecedented encouragement and patronage which 

 the work has experienced. When he began to publish 

 the Anyials he was well acquainted with the state of the 

 scientific publications of this metropolis, and of the 

 difficulty of venturing a competition with works that 

 had been before the public for 16 or 17 years. Indeed 

 he was warned by several of his friends, for whose 

 judgment he has the highest respect, that the ground 

 was pre-occupied, and that success was not to be 

 looked for. He hoped however that, by bestowing 

 an unusual degree of labour and attention upon the 

 Annals of Philosophy, and by confining it to original 

 papers, or translations of foreign papers supposed to 

 be unknown to the generahty of the British public, he 

 should by degrees establish a journal of so novel a kind 

 as scarcely to be considered as a rival to the other 

 scientific and periodical publications of Great Britain, 

 and claiming attention from the value of the informa- 

 tion which it would communicate. The result has 

 ^howii that this opinion was not without foundation ; 

 though the Editor acknowledges with pleasure, and 

 not without a feeling of pride, that the success of the 

 work has been much more rapid, and the attention 

 paid to it by men of science much greater, than he 

 had expected. Of the articles in this volume 115 are 

 original papers which made their first appearance in 



