I say, with Cicero—Tacere prcestat philosoplkis^
>quam loqui. To those who may ingenuously desire
to correct errors, and who possess manliness suffi-
cient to offer judicious advice, I shall give my
cordial thanks, knowing how to appreciate an im-
partial critique. Palmam qui meruit ferat.—"Be,
his the palm who merits it."

If my work meets with a favorable reception, and
is considered useful, I shall feel happy in having at-
tained my most ardent wishes ; I shall forget the toils,
dangers, and sacrifices I have undergone, and, more-
over, escape the lot of many, who, after having spent
the greater portion of their lives and fortune, and,
not unfrequently, ruined their health, in rendering
themselves useful to mankind, have too often met
with ingratitude, and, sometimes, with persecution.
Many benefactors of the human species have ex-
perienced such treatment, and analogy almost pre-
pares us to expect it. If we turn to the histories of
important discoveries and inventions, we shall find,
that, on their firs.t announcement, they were con-
temned and ridiculed, while the inventors and dis-
coverers were laughed at, misrepresented, and vilified.
Sydenham, whose memory we must revere, was, by
several of his contemporaries, stigmatized with the
-name of quack, and murderer. Many now celebrated
men, who, in the fourteenth century distinguished
themselves by their knowledge of physical science,
were burned as sorcerers. Galileo was imprisoned
in his seventieth year, for maintaining the rotation of
the earth ; and posterity may, perhaps, admire some
of our cotemporaries, who having done much for the
advancement of arts and sciences, have not enjoyed
the esteem they merit