"It is surprising how little the majority of people value sunlight. It is not the visible sunlight that performs the wonders in giving strength to man. If you recall, we spoke about the actinic rays which cause the chemical changes on the photographic plate. It is those unseen rays which produce the aurora borealis, exert a curative effect upon leprosy and tuberculosis, fill the atmosphere on the sunny side of a street with oxygen and nitrogen, and do many other marvelous things."
"In what manner does the invisible light produce these results?"
"In its sparkling radiations microbes die, decay ceases, the iron in the blood becomes chemically strong; ozone is manufactured from the dirt and dust, which are also destroyed; the perspiration becomes active and carries off waste from the muscles and cleanses the skin; dead tissues are purified and the muscles invigorated; and all life is made to thrive."
"Does the sunlight have the same effect on all the animal creations?"
"This is true of all animate life, except minute organisms, or what are called bacteria."
"If that is the case, why do worms and the like hide themselves in the earth?"
"In that case it is the instinct of self-preservation. The most of them are eyeless, so that sunlight exposes them to birds and other enemies. Professor Mast demonstrated that they are very favorably influenced by exposure to sunlight. Dr. Dolly has shown, by a series of very brilliant experiments, that the butterfly will live three times longer in sunlight than in the shadow; and Professor Yerkes has also proven that the jellyfish, while inactive in the dark, becomes very strenuous in sunlight."
"If that is the case, why wouldn't it be a good thing to have all houses made of glass?"
"That is really what has been proposed. The Government of the United States has set a good example in this respect by devoting over one-half of the space of the new post-office building in Washington to an arrangement which permits the interior to be flooded with sunlight."
In the really strenuous times which our colonists had passed through the pleasures of fishing had been forgotten, and as that was an article of food which all relished, and of which they had been deprived for some time, Harry insisted that at least a portion of the following day should be spent in that way.