THE 



ECONOMY OF NATURE 



EXPLAINED AND ILLUSTRATED 



OS THE 



PRINCIPLES 



O F 



MODERN PHILOSOPHY. 



B V 



G. GREGORY, D.D. 



AUTHOR OF 



ESS ATS HISTORICAL AND MORAL, fifc. 



IN THREE VOLUMES. 

 WITH FIFTY-SIX PLATES. 



The SECOND EDITION, with confiderable Additions, 



VOL. II. 



LONDON: 



PRINTED FOR J. JOHNSON* N 72, ST. fAUl's CHURCH TARB. 



