Sunshine and Health in Different Lands

Abstract

I AM indebted to the editor for the opportunity to reply at once to Miss Botley's comments on my letter to NATURE of April 5. It would, indeed, be “undesirable to take the question of sunlight apart from other climatic effects.” The whole purpose of my letter was to express a warning against one-sided statements of a many-sided case, and to suggest that if combined efforts were made to discover how different countries compare with an optimum allowance of sunshine, if possible, to be evaluated, the local problems of sunshine therapeutics would be greatly clarified. Apparently there is, or used to be, a belief in India, the Philippines, and other tropical lands, that excessive stimulation by the ultra-violet rays of the sun should be specially guarded against by suitably-coloured clothing, and this in itself would raise the question of an optimum, and of the need of investigating the subject in its geographical relationships, in view of recent pronouncements upon the therapeutic importance of ultra-violet light in temperate latitudes.