vl TRANSLATORS' PREFACE. 



ticulars, which disclose to us much of the in- 

 terior spirit of the Academy of Sciences, not 

 always of a kind the most creditable to some 

 of Arago's former contemporaries. 



But a far higher interest will be found to 

 belong to those eloquent memoirs, or eloges of 

 eminent departed men of science, who had at- 

 tained the distinction of being members of the 

 Academy. 



In these the reader will find a luminous, 

 eminently simple, and popular account of the 

 discoveries of each of those distinguished indi- 

 viduals, of a kind constituting in fact a brief 

 history of the particular branch of science to 

 which he was devoted. And in the selection 

 included in the present volume, which consti- 

 tutes but a portion of the entire series, we have 

 comprised the accounts of men of such varied 

 pursuits as to convey no inadequate impression 

 of the progress of discovery throughout a con- 

 siderable range of the whole field of the physi- 

 cal sciences within the last half century. 



The account given by the author, of the prin- 

 cipal discoveries made by the illustrious subjects 

 of his memoirs, is in general very luminous, 

 but at the same time presupposes a familiarity 

 with some parts of science which may not 

 really be possessed by all readers. For the 



