Resistance to disease is secured by building a strong body, providing it with fresh, pure food properly adjusted to the age, sex, size, work of the person, and to climate and season, and by insuring an environment of such wholesomeness and cleanliness as will supply to all pure water and air and stamp out disease-sources, such as unsanitary disposal of garbage.

Preventive medicine removes disease-dangers from the environment and increases body-resistance. Conditions of living are of first importance. No body can be well nourished save as food is available. Protection against disease comes with provision for living. Illness is found to be social in its effects and causes. An ill person is a general health-menace.

A debilitating disease prevalent in the South, science says, requires, for elimination of it, nourishing food, sanitary disposal of sewage, and that children should wear shoes to prevent contagion from soil-contamination by waste products from those so diseased.

Natural immunity to disease-infection increases for children with age. The composition of the body changes; its water-content decreases. The excess of water in an infant's body lowers resistance to infection. To lessen this, milk may be decreased for a child after one year to the amount in adult-diet. Carbohydrate food increases the water in the body (Cernzy).

Constitutional inferiority opens a body to disease. Diet may minimize this. Secretions of the ductless glands of the body are now known to affect body-growth and health. Disturbed nutrition may cause defective development of these glands and in turn be caused by their resulting defective functioning. Mature health is thus endangered and work-endurance lessened.

Mineral salts effect nutrition as well as furnish material for teeth and bone-growth. A mixed diet provides food salts during adult-health, but not always in illness and childhood.