THE

PROBLEM OF HUMAN LIFE:

EMBRACING THE

"EVOLUTION OF SOUND" AND "EVOLUTION EVOLVED,"

WITH

A REVIEW OF THE SIX GREAT MODERN SCIENTISTS,

DARWIN, HUXLEY, TYNDALL, HAECKEL,
HELMHOLTZ, AND MAYER.

TWENTIETH REVISED EDITION.

BY. A. WILFORD HALL.

NEW YORK:

HALL AND COMPANY,

139 EAST 8TH STREET.

Entered, according to Act of Congress, in the year 1877, by

HALL & CO.,

in the Office of the Librarian of Congress, at Washington. D.C.

1382

33.747

DEDICATION.

To the Reader of this book, who may conscientiously

desire to arrive at the Truth, and nothing but the Truth, con

cerning the several matters herein discussed, the following pages are affectionately inscribed by

THE AUTHOR.