The Montgomery advertiser., 1903-12-27
Why the Sky Is Blue
By J. A. B. Lovett, A. M, Ph. D.

Who has not asked himself the ques- tion, Why is the sky blue?' From our earliest remembrance we have been told tha. the sky is blue because 1t is as far as We can see. All must admit that this is an explanation that does not explain. Why not some other co.or. as red or green? The mere limit of vision cannot account for the color of anything.
 In my opinion, after much careful thought and investigation the sky gets its cerulean hue from the presence of oxygen in the atmosphere. But all the authors on chemical science, tell us that oxygen Is colorless. If 1t can be shown, by a reasonable supposition, that the "colorless' idea is not true, the very color of the sky itself stands out as a strong witness, corroborating the proposition that oxygen is blue. I am aware of the fact that the limited volume of oxygen gas usually generated in the laboratory, have no perceptible color. But are we to con- clude that a physical property of sub- stance is absent, simply because we have not a sufficiently acute subjective power Co appreciate 1t? Are there not sound waves that are too feeble to stimulate tEe auditory nerves? Are there not particles of matter too delicate to be apprehended by the most sensitive power of touch Are there not matters of taste that wholly . And odors, that never reach the olfactory nerves? Now, if it bo true that much of our sense-knowledge is lost before 1t reaches the threshold of sensing power, we cannot. with any degree of scientific truth, conclude that the subjective testi- mony, alone, can decide upon all questions of physical properties of matter. To do this, would be to eliminate from science the broad fields of both microscopic and telescopic investigations. The truth is, the special human senses, when compared with those of many of the lower animals and insects, are quite dull; and, because of the, fact that many concepts are not formed by us, subjectively on account of this dullness, we are not to conclude that such concepts may not have a logical ba- sis, objectively. pinch of salt in gall lon of water may not be recognized by the sense of taste; yet, who would deny the objective salivity of the water? So with oxygen. A small volume of this gas Is without perceptible color; but great banks of 1t, as in the atmosphere, shows that the color is blue. An illustration of this may be seen in visual experiments with panes of common glass. Look through a single pane. and we say 1t s colorless. Place a dozen or more panes together, and a decided green tint is ob- served.
 While they may not be regarded as conclusive evidence to the chemist, I hold that the following phenomena are strong corroborative proofs of the conclusion here presented, that oxygen Is blue:
 F'irst-A small beaker of pure water is rolorless; a large class vessel. filled with the same substance, is blue. True. com pound is not necessarily the same color as the elements not in combinations; but In this case, the compound H2O is blue. Connect this fact with the color of the sky.
 Second-It is we'll known that oxygen, when liquifed, is of a deep blue color. Now, in the returning of liquid oxygen to khe gaseous state. there Is no chemical change-it is only a physical change. From this fact, the related fact is in mind: that the change from the gaseous state to the liquid. there is no chemical rhange-it is merely physical change.