Page:Popular Science Monthly Volume 20.djvu/556

540 new environment, so the philosopher has advanced, step by step, until he seems almost to have grasped the ultimate particles which constitute the physical basis of the universe, and to have rendered visible to mortal unaided eyes particles of matter which are not only invisible by the aid of the most powerful microscope, but are too infinitesimal even for the mind's eye to conceive.

When that marvelous little instrument called the spectroscope was devised, it seemed that man had invaded fairy-land and stolen "a trap to catch a sunbeam," for such it is, in very truth: not only does it catch the dancing sheaf of light, but spreads it out into a band of exquisite colors and exhibits to our fascinated gaze Nature's palette of purest tints, out of which is woven the whole fabric of the gorgeous sunset, the variegated flowers, the bright plumage of the birds, the iridescence of mother-of-pearl, the sparkle and hue of gems, and, indeed, every variety of color in nature or in art.

But this little instrument is still more wonderful, for it combines with its qualities of a trap the advantages of a balance which we may suppose is fine enough for the most fastidious fairy to weigh the nectar distilled in the dew-drop, or other delicacy of the season.

Our ideas of weight and size are purely relative, and that which seems a small or light object, from one point of view, may become large and heavy by a different comparison. To most of us, perhaps, a "grain-weight" suggests a little thing; we know that the apothecary and a few other small dealers split up the grain into halves, quarters, tenths, and perhaps even hundredths, but then we regard them as homœopathic visionaries and laugh at their absurd little pellets; yet, strange to say, there is a vanishing-point in our minds, which, if an object is small, enough to pass, it becomes larger and more important by reason of our astonishment and wonder at its minuteness: the most ordinary specimen under the microscope is an evidence of this, but when we realize that the ability of the spectroscope to reveal small particles of matter begins where the finest microscope searches with its highest power in vain, that the grain of matter may be divided, not merely into hundredths, or thousandths, or tens of thousandths, but into millionths and tens of millionths, and that a single one of these particles may be readily detected by this little searcher and held up for our inspection, our wonder and amazement enhance our respect for its occult powers. The astronomer tells us that a comet often throws out a tail longer than the distance between the earth and the sun, and broad in proportion; yet the matter forming this tail is so attenuated that, if properly compressed, a gentleman's portmanteau, possibly his snuff-box, might take it in. Yet we have merely to point this little tell-tale at the comet, and, presto! we know what the matter is. Think of it! Not merely can we grasp infinitesimal particles at our hand, but we may sweep the firmament, gather up the star-dust and tell its composition.