GEORGE HARLEY, M.D.,

Professor of Medical Jurisprudence in University College, London; Assistant Physician to University College Hospital; Formerly President of the Parisian Medical Society; Cor. Memb. of the Academy of Sciences of Bavaria, and of the Royal Academy of Medicine of Madrid.

So rapid is the advance of science, that the theory regarded as true to-day, may be recognised as false to-morrow. The facts, however, on which the theory is based, if rightly observed, remain unaltered, and unalterable.

LONDON:
WALTON AND MABERLY,
UPPER GOWER STREET, AND IVY LANE, PATERNOSTER ROW.
MDCCCLXIII.

LONDON:
WILLIAM STEVENS, PRINTER, 37, BELL YARD,
TEMPLE BAR.

TO
WILLIAM SHARPEY, M.D., LL.D., F.R.S.,
Professor of Anatomy and Physiology in University College, London,
AS
A SMALL TOKEN OF A COLLEAGUE'S ESTEEM
FOR
A PROFOUND THINKER, A SOUND REASONER,
AND
A TRUE FRIEND.