Sunlight is also especially important during puberty and adolescence, when profound internal reorganizations are taking place.

After a fast or a wasting illness, when it is desired to build up a lot of flesh, sunlight will aid in building the best kind of flesh.

It is asserted by some that sunshine enables the body to manufacture vitamin A. The theory has been advanced by Saleeby that the skin is an organ of internal secretion and that as suggested by Sheridan Delepine, under the influence of sunshine it contributes to the making of hemoglobin. He insists that in the pigmented skin, under the influence of sun-light, very active chemical processes are occurring.

If this view proves correct, it will justify Graham's attachment of so great importance to its effects upon the skin. Others think they have found that by the aid of sunshine the body manufactures a substance called cholestrin which is essential to calcium metabolism. Whichever way we turn the emphasis is on nutrition.

We can no longer relegate to an inferior position an element of hygiene which has so important and so necessary an influence on health and growth. Yet, "noon lulls us in a gloomy den, and night is grown our day."

After reviewing the evidence possessed in his day, Trall declared "these facts show us that light, and an abundant supply of it, is indispensable to a due development of all organized bodies." This statement expresses the fundamental difference between the ortho-bionomic use of sunshine and its medical use.

Due to the fact that sunshine is an essential of healthy nutrition, being necessary to growth, development and repair of tissue, it is of value in all states or conditions of the body. It is not a specific "cure" for one or two so-called "specific diseases," as the medical profession teaches. It is a hygienic, not a therapeutic agent, and is needed as well in health as in conditions of impaired health. It is needed by the healthy, growing, developing child, the pregnant or nursing mother, the chronic invalid, the convalescing patient, the athlete, and by all who desire to maintain or regain health. It is an important aid in building and maintaining health and we should not wait until we become sick to make use of it.

Trall and Taylor studied sunlight as food--not as an essential in certain states of impaired health, but as an indispensable elemental condition of continued active life and normal development and function. It is this difference in viewpoint of the two schools that accounts for the difference of application. Hygienists lay great stress upon sunshine--to the medical man it is of small importance.