12 MAGIC OF SUNLIGHT 



In nature there are permanent colours like 

 those of the night, and transient hues like 

 those of the sunrise or sunset. So the blue 

 of the sky and yellow of the earth make the 

 green of living plants which seems to be per- 

 manent until, in decay, the blue turns out to be 

 transient, and passes away leaving the herbage 

 yellow. It is odd that the natural food of the 

 horse is dried herbage from which the blue 

 has faded, 



And so it is with man. We may eat green 

 salads, containing transient blue, but the 

 permanent colours of our food are free from 

 blue, and based on red and yellow. Neither 

 horse nor man would fatten on blue food. 



Sunlight shining through blue glass will stop 

 the growth of plants. The various actions of 

 coloured light upon the human body are being 

 studied in many hospitals. 



The blue indigo and violet, or actinic rays, 

 appear to have a special mission in burning 

 bad microbes, such as the germs of disease. 

 A green forest, for example, despite the per- 

 manent yellow in its colour, is said to be partly 

 transparent to these rays which kill germs 

 lurking in the soil. The flesh of men and 

 beasts is red and yellow, save only for the 

 blue tinge of blood from which the oxygen has 



