Tiii PREFACE 



whatever is most valuable in the Original Work;* and that to those who are 

 necessarily engaged in philosophical pursuits in the way of their profession, 

 as well as to those who in their hours of leisure cultivate the sciences from 

 taste, it will, up to the period which it embraces, be found to answer all 

 the purposes of the more costly and scarcely procurable Transactions at 

 large. 



* With the exception of certain papers before-mentioned, which have been reprinted in other 

 works of easy access, and to which, in this Abridgment, reference has always been made. 



London, Jpril 26, 1809. 



