THE Historical Introductions, prefixed by Professor BARLOW to his Treatises on 

 the Physical Sciences, contained in the Second Division of the Encyclopedia Metro- 

 politana, are frequently referred to in Professor WHEWELL'S History of Greek 

 Mathematics, which precedes this article'. The following- passages have, on that 

 account, been extracted from those Treatises and appended here, for the sake of easy 

 reference. The last of the six extracts is made from the ' History of Electricity,' 

 by the late Rev. FRANCIS LUNN. The reader who desires further information than 

 is afforded by the passages now cited, is referred to the History of Greek Physics, 

 contained in the History of the Inductive Sciences, by Professor WHEWELL. 

 EDITOR. 



