Celestial Chemistry. 399 



fering, the one from the other, in the kinds of matter of which 

 they consist, are all constructed upon the same plan as our 

 sun, and are composed of matter identical, at least in part, 

 with the materials of our system. 



" The differences which exist between the stars are of the 

 lower order of differences of particular adaptation, or special 

 modification, and not differences of the higher order of distinct 

 plans of structure. 



" There is, therefore, a probability that these stars, which 

 are analogous to our sun in structure, fulfil an analogous pur- 

 pose, and are, like our sun, surrounded by planets, which they 

 by their attraction uphold, and by their radiation illuminate 

 and energize. And if matter identical with that upon the 

 earth exists in the stars, the same matter would also probably 

 be present in the planets genetically connected with them, as is 

 the case in our solar system. 



" It is remarkable that the elements most widely diffused 

 through the host of stars are some of those most closely con- 

 nected with the constitution of the living organisms of our 

 globe, including hydrogen, sodium, magnesium, and iron. Of 

 oxygen and nitrogen we could scarcely hope to have any deci- 

 sive indications, since these bodies have spectra of different 

 orders.* These forms of elementary matter, when influenced 

 by heat, light, and chemical force, all of which we have certain 

 knowledge, are radiated from the stars, afford some of the 

 most important conditions which we know to be indispensable 

 to the existence of living organisms, such as those with which 

 we are acquainted. On the whole, we believe that the fore- 

 going spectrum observations on the stars contribute something 

 towards an experimental basis, on which a conclusion, hitherto 

 but a pure speculation, may rest, viz., that at least the brighter 

 stars are, like our sun, upholding and energizing centres of 

 systems of worlds adapted to be the abode of living beings." 



THE NEBULA. 



By far the most wonderful of the revelations of spectrum 

 analysis applied to the heavenly bodies has yet to come. En- 

 couraged by his success with the fixed stars, Mr. Huggins 

 resolved to apply this new and potent method of research to 

 the examination of those mysterious bodies, the Nebulas, and 

 this investigation was rewarded by one of the most important 

 discoveries connected with the physical constitution of those 

 wonderful objects, and with the cosmical origin of the universe, 

 which we venture to think has ever been made. From the 

 time of Sir W. Herschel, who took up Messier' s scanty list of 



* That is, differ entirely at different temperatures and pressures. 



