Tacoma, Wash., for his question:

IS MILK A LIVING SUBSTANCE?

Rather than call milk a living substance, it should be called the most nourishing of all foods. It has almost all of the nourishing substances that are needed by people for good health and growth.

All female mammals produce milk for their young. But when we think of milk, we usually are referring to milk that comes from cows. In a great many parts of the world, cows or goats provide the bulk of milk that is used as food.

For energy, growth and replacing worn-out tissue, the body needs carbohydrates, fats, minerals, proteins and vitamins. Milk is nearly the perfect food since it supplies most of these requirements. Missing only is part of the body's mineral and vitamin requirement.