126 NATURE AND LIFE. 
is quite certain that green light is a very lively and health- 
_ ful stimulant for our functions, and that, for that BeaEOH; 
spring is the favored and enchanted season. 
The correspondence between perfection of forms and 
heightening of luminous intensity proves true in the hu- 
man race as in others. Aisthetics, agreeing with ethnog- 
raphy, demonstrate that light tends to develop the differ- 
ent parts of the body in true and harmonious proportion. 
Humboldt, that nice observer, says, speaking of the Chay- 
mas: “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 thousands of Caribs, Muy- 
cas, 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, es- 
pecially among people who have a deep-colored skin.” 
No doubt there is a great difficulty in conceiving how light 
can model—can exert a plastic power. Yet, reflecting on 
its tonic effect on the outer tegument, and its general infiu- 
ence over the functions, we may assign it the part of dis- 
tributing 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their bodies are withdrawn from the vivifying action of 
solar radiation. Thence follows an equilibrium which se- 
cures regularity in function and development. 
It is commonly said that an ordained causality rules the 
operations of matter, and that free spontaneity is the privi- 
lege of those of spirit. It might well be said on this sub- 
ject that, in many cases, the causes acting in matter elude 
us, and, not less often, the causes which act in spirit over- 
power us; but it is not our task to elucidate that terrible 
antithesis of law, when the genius of Kant failed in it. 
We would only ask it to be observed how great an influ- 

