LECTURER ON PHOTOGRAPHY IN KING'S COLLEGE, LONDON;
LATE DEMONSTRATOR OF CHEMISTRY IN KING'S COLLEGE.

Fourth Edition.

LONDON:
JOHN CHURCHILL, NEW BURLINGTON STREET.
MDCCCLVII.

[The Author reserves to himself the right of translating this Edition.]

PRINTED BY
JOHN EDWARD TAYLOR, LITTLE QUEEN STREET,
LINCOLN'S INN FIELDS.