3 20 THE POPULAR SCIENCE MONTHLY. 



sequence by imperfection in our methods of nomenclature, the confu- 

 sion in this respect becoming, as we all too well know, every day 

 worse and worse. 



And now, while we have accomplished only a most imperfect ex- 

 amination of objects that we find on the earth, see how, on a sudden, 

 through the vista that has been opened by the spectroscope, what a 

 prospect lies beyond us in the heavens ! I often look at the bright- 

 yellow ray emitted from the chromosphere of the sun, by that unknown 

 element, Helium, as the astronomers have ventured to call it. It 

 seems trembling with excitement to tell its story, and how many un- 

 seen companions it has. And if this be the case with the sun, what 

 shall we say of the magnificent hosts of the stars ? May not every 

 one of them have special elements of its own ? Is not each a chemical 

 laboratory in itself? Look at the cluster in the sword-handle of Per- 

 seus; in Cassiopeia, a universe of stars on a ground of star-dust; in 

 Hercules of which, as astronomers say, no one can look at for the first 

 time through a great telescope without a shout of wonder the most 

 superb spectacle that the eye of man can witness ! Look at the double 

 stars of which so many are now known, emitting their contrasting 

 rays, garnet, or ruby, or emerald, or sapphire. Each is in accordance 

 with its own special physical conditions, though all are under the 

 same universal ordinance. 



Now, here a fact of surpassing importance presses itself on our 

 attention. The movements taking place in those distant bodies are 

 taking place under the same laws that prevail here on earth, and in 

 our solar system. The law of gravitation, as developed by Newton, 

 bears sway in all those distant worlds. In them bodies attract each 

 other with forces directly as their masses and inversely as the squares 

 of their distances. There the laws of the emission, absorption, and 

 transmission of light are the same as they are with us. There ignited 

 hydrogen gives forth its three rays, the same rays that it gives forth 

 to us. In the uttermost parts of the universe the law of definite com- 

 bination, the numerical law, and the multiple law, stand good. So- 

 dium absorbs its two waves of definite refrangibility, and iron gives 

 in the spectra its # more than a hundred lines, more than a hundred 

 silent but convincing witnesses of the uniformity of the constitution 

 of the universe. There the number of vibrations that constitute a ray 

 of definite refrangibility is the same we have found it to be here. In 

 the enormous heat of those central suns the dissociation of molecules 

 may be of a higher order than we can reach artificially, but the law 

 under which it takes place is a continuation of the law here. There, 

 though the weight of a given mass of matter is different from what it is 

 with us, it is nevertheless determined by the law that determines here 

 the law of gravitation. There energy is indestructible, and is measured 

 as it is measured among us, by work. Then is there any boundary 

 that we can assign to natural law is it not omnipresent, universal ? 



