s true that a moderate infraction of some of the minor rules
of health is not inconsistent with maintaining good health in the sense
of keeping out of a sick-bed, such infraction, be it ever so moderate,
is utterly inconsistent with good health in the sense of attaining the
highest physical and mental efficiency and power.

Future advances of knowledge will doubtless occasion additions to, or
modifications of, the conclusions stated herein, and these will form the
subject of subsequent publications by the Institute.

In order that the Institute may have at its disposal the latest and most
authoritative results of scientific investigations, its Hygiene
Reference Board was created. The present book is the first general
statement of the conclusions of this Board after a year of careful
consideration. These conclusions are the joint product of the members of
the Board, with the active co-operation of the Director of Hygiene of
the Institute. They may fairly be said to constitute the most
authoritative epitome thus far available in the great, but hitherto
neglected, realm of individual hygiene.

The Chairman of the Board has exercised the function of editor, and is
responsible for the order and arrangement of the material.

Friends of the Institute may help its work by spreading the ideas given
in the following pages and by increasing the number of its readers. Such
profits as may be received by the Institute from the sale of this book
will be devoted to further philanthropic effort by the Institute.

IRVING FISHER,
EUGENE L. FISK.

New York, Sept., 1915.

CONTENTS

PAGE

INTRODUCTION 1

CHAPTER I

AIR

SECTION
1. HOUSING 7
2. CLOTHING 14
3. OUTDOOR LIVING 18
4. OUTDOOR SLEEPING 20
5. DEEP BREATHING 24

CHAPTER II

FOOD

1. QUANTITY OF FOOD 28
2. PROTEIN FOODS 35
3. HARD, BULKY, AND UNCOOKED FOODS 40
4. THOROUGH MASTICATION 44

CHAPTER III

POISONS

1. CONSTIPATION