The term Physiology, or the science of the functions of the body, has come
to include Anatomy, or the science of its structure, and Hygiene, or the
laws of health; the one being essential to the proper understanding of
physiology, and the other being its practical application to life. The
three are intimately blended, and in treating of the different subjects
the author has drawn no line of distinction where nature has made none.
This work is not prepared for the use of medical students, but for the
instruction of youth in the principles which underlie the preservation of
health and the formation of correct physical habits. All else is made
subservient to this practical knowledge. A simple scientific dress is used
which, while conducing to clearness, also gratifies that general desire of
children to know something of the nomenclature of any study they pursue.

To the description of each organ is appended an account of its most common
diseases, accidents, etc., and, when practicable, their mode of treatment.
A pupil may thus learn, for example, the cause and cure of "a cold," the
management of a wound, or the nature of an inflammation.

The Practical Questions, which have been a prominent feature in other
books of the series, will be found, it is hoped, equally useful in this
work. Directions for preparing simple microscopic objects, and
illustrations of the different organs, are given under each subject.

The Readings, which represent the ideas but not always the exact
phraseology of the author quoted, have, in general, been selected with
direct reference to Practical Hygiene, a subject which now largely
occupies the public mind. The dangers that lurk in foul air and
contaminated water, in bad drainage, leaky gas pipes, and defective
plumbing, in reckless appetites, and in careless dissemination of