LIGHT AND LIFE. 305 



ences acting at once, and light does not play the sole part in them. 

 Heat and other conditions of the medium probably have a share in 

 these operations of color. Still, the peculiar and powerful effect of 

 luminous radiation as a part of them is beyond dispute. 



The whole system of organic functions shares in the benefits of 

 light. Darkness seems to favor the preponderance of the lymphatic 

 system, a susceptibility to catarrh in the mucous membranes, flaccidity 

 of the soft parts, swellings and distortions of the bony system, etc. 

 Miners and workmen employed in ill-lighted shops are exposed to all 

 these causes of physiological suffering. We may notice, with regard 

 to this, that certain rays of the solar beam affect animals like darkness ; 

 among others, the orange light, which, according to Bert, hurts the de- 

 velopment of batrachians. Now, if this light is injurious to animals, 

 it is not so to plants, as we have seen. In exchange, green light, 

 which is hurtful to vegetables, is extremely favorable to animals. 

 There is a kind of opposition and balance, then, as respects luminous 

 affinities, between the two great kingdoms of life. White light, as 

 Dubrianfant says, seems to split up under the influence of living be- 

 ings into two complementary groups, a green group and an orange 

 group, which exhibit in Nature antagonistic properties. It is quite cer- 

 tain that green light is a very lively and healthful stimulant for our 

 functions, and that, for that reason, spring is the favored and enchanted 

 season. 



The-correspondence between perfection of forms and heightening of 

 luminous intensity proves true in the human race as in others. Es- 

 thetics, agreeing with ethnography, demonstrate that light tends to de- 

 velop the different parts of the body in true and harmonious propor- 

 tion. Humboldt, that nice observer, says, speaking of the Chaymas : 

 " The men and women have very muscular bodies, but plump, with 

 rounded forms. It is needless to add that I have never seen a single 

 one with any natural deformity. I will say the same of so many thou- 

 sands of Caribs, Muycas, Mexican and Peruvian Indians, whom we 

 have observed during five years. These bodily deformities and mis- 

 growths are extremely rare in certain races of men, especially among 

 people who have a deep-colored skin." No doubt there is great diffi- 

 culty in conceiving how light can model can exert a plastic power. 

 Yet, reflecting on its tonic effect on the outer tegument, and its gen- 

 eral influence over the functions, we may assign it the part of distribut- 

 ing the vital movement orderly and harmoniously throughout the 

 whole of the organs. Men who live naked are in a perpetual bath of 

 light. None of the parts of their bodies are withdrawn from the vivi- 

 fying action of solar radiation. Thence follows an equilibrium which 

 secures regularity in function and development. 



It is commonly said that an ordained causality rules the operations 

 of matter, and that free spontaneity is the privilege of those of spirit. 

 It might well be said on this subject that, in many cases, the causes 



