THE

ECONOMY OF NATURE

EXPLAINED AND ILLUSTRATED

ON THE

PRINCIPLES

O F

MODERN PHILOSOPHY.

BY

G. GREGORY, D. D.

AUTHOR OF

ESSAYS HISTORICAL AND MORAL, &c.

IN THREE VOLUMES.

WITH FIFTY-SIX PLATES.

The SECOND EDITION, with confiderable Additions.

VOL. III.

LONDON:

PRINTED FOR J. JOHNSON, N° 72, ST. PAUL'S CHURCH YARD,