OF MAN 261

Object; Human and Animal Feeding Compared; Standard
Rations; Why Tentative Dietary Standards; Amounts
of Food Consumed; Average Composition of Foods;
Variations in Composition of Foods; Example of a Ration;
Calculations of Balanced Rations; Requisites of a
Balanced Ration; Examples; Calculations of Rations for
Men at Different Kinds of Labor.

CHAPTER XIX

WATER 268

Importance; Impurities in Water; Mineral Impurities;
Organic Impurities; Interpretation of a Water Analysis;
Natural Purification of Water; Water in Relation to
Health; Improvement of Waters; Boiling of Water; Filtration;
Purification of Water by Addition of Chemicals;
Ice; Rain Waters; Waters of High and Low Purity;
Chemical Changes which Organic Matter of Water Undergoes;
Bacterial Content of Water; Mineral Waters;
Materials for Softening Water; Uses of; Economic Value
of a Pure Water Supply.

CHAPTER XX

FOOD AS AFFECTED BY HOUSEHOLD SANITATION AND
STORAGE 284

Injurious Compounds in Foods; Nutrient Content and
Sanitary Condition of Food; Sources of Contamination
of Food; Unclean Ways of Handling Food; Sanitary Inspection
of Food; Infection from Impure Air; Storage
of Food in Cellars; Respiration of Vegetable Cells; Sunlight,
Pure Water, and Pure Air as Disinfectants; Foods
contaminated from Leaky Plumbing; Utensils for Storage
of Food; Contamination from Unclean Dishcloths; Refrigeration;
Chemical Changes that take Place in the
Refrigerator; Soil; Disposal of Kitchen Refuse; Germ
Diseases spread by Unsanitary Conditions around Dwellings
due to Contamination of Food; General Considerations;
Relation of Food to Health.

CHAPTER XXI

LABORATORY PRACTICE 299

Object of Laboratory Practice; Laboratory Note-book
and Suggestions for Laboratory Practice; List of Apparatus
Used; Photograph of Apparatus Used; Directions
for Weighing; Directions for Measuring; Use of Microscope;
Water in Flour; Water in Butter; Ash in Flour;
Nitric Acid Test for Nitrogenous Organic Matter; Acidity
of Lemons; Influence of Heat on Potato Starch Grains;
Influence of Yeast on Starch Grains; Mechanical Composition
of Potatoes; Pectose from Apples; Lemon Extract;
Vanilla Extract; Testing Olive Oil for Cotton Seed Oil