THE STORY OF ARTIFICIAL SILK as plants and animals. We must have sun- light and fresh air. The main health factors are sunlight on the body, fresh air in the lungs and sound unbroken sleep. Savages have more of all three than we civilized people have. Suppose I were to civilize a cabbage ! Suppose I transplanted it into my drawing- room and put a suit of woollen or cotton clothes on it | What would be the fate of that cabbage ? It would not grow. It would wither and die. Suppose we put sun-resisting clothes on apples or marrows or dogs! They would be injured, not helped. Every living thing needs the whole of the sunlight and continual fresh Air. The semi-naked races have no knowledge of science nor hygiene. They live in the midst of smells. They drink foul water. They know nothing of germs. But they live fairly long and are amazingly strong and healthy. Why ? Because they have a PLus which we lack. They have the Ultra-Violet rays on the skin of the whole body. This one advantage helps to pull them through and gives them a hardihood that civilized 2