428 FRAGMENTS OF SCIENCE* 
were particles, small in comparison to the sizes of the ether 
waves, sown in our atmosphere, the light scattered by 
those particles would be exactly such as we observe in our 
azure skies. When this light is analyzed, all the colors of 
the spectrum are found, and they are found in the pro- 
portions indicated by our conclusion. Blue is not the sole, 
but it is the predominant color. 
Let us now turn our attention to the light which passes 
unscattered among the particles. How must it be finally 
affected? By its successive collisions with the particles the 
white light is more and more robbed of its shorter waves; 
it therefore loses more and more of its due proportion of 
blue. The result may be anticipated. The transmitted 
light, where short distances are involved, will appear 
yellowish. But as the sun sinks toward the horizon the 
atmospheric distances increase, and consequently the 
number of the scattering particles. They abstract in 
succession the violet, the indigo, the blue, and even disturb 
the proportions of green. The transmitted light under 
such circumstances must pass from yellow through orange 
to red. This also is exactly what we find in nature. 
Thus, while the reflected light gives us at noon the deep 
azure of the Alpine skies, the transmitted light ives us at 
sunset the warm crimson of the Alpine snows. The 
phenomena certainly occur as if our atmosphere were a 
medium rendered slightly turbid by the mechanical sus- 
pension of exceedingly small foreign particles. 
Here, as before, we encounter our skeptical "as if." 
It is one of the parasites of science, ever at hand, and ready 
to plant itself and sprout, if it can, on the weak points of 
our philosophy. But a strong constitution defies the 
parasite, and in our case, as we question the phenomena, 
probability grows like growing health, until in the end the 
malady of doubt is completely extirpated. The first 
question that naturally arises is this: Can small particles 
be really proved to act in the manner indicated? No 
doubt of it. Each one of you can submit the question to 
an experimental test. Water will not dissolve resin, but 
spirit will dissolve it; and when spirit holding resin in 
solution is dropped into water, the resin immediately 
separates in solid particles, which render the water milky. 
The coarseness of this precipitate depends on the quantity 
of the dissolved resin. You can cause it to separate either 
