NATURAL PHILOSOPHY. 133 



to bring out the highly refrangible lines observed in photographs of 

 the magnesium spectrum. 



There were thirteen bodies known on earth, which these researches 

 lead us to suppose existed in the solar atmosphere. Nor are they lim- 

 ited merely to the sun. Fraiinhofer, had examined the spectra of sev- 

 eral stars, and found that, although they presented no similarity to that 

 of the sun, nor to each other, yet that some general relationship between 

 them was observable. Mr. Huggins and the lecturer had recently 

 been investigating this subject, and had obtained very perfect maps of 

 the visible spectra of several stars. They had also obtained a photo- 

 graph of the spectrum of Sinus. This star is 130,000,000,000 of miles 

 distant, and the light, which produced the photograph must have left 

 it twenty-one years ago. 



_ A photograph of the spectrum of Capella, which is three times further 

 distant than Sirius, had also been obtained, the light to produce which, 

 the lecturer said, must have left that star when the oldest in the room 

 was a little boy. 



Spectrum Analysis applied to the Stars. In a communication 

 published in the Intellectual Observer (London), by Mr. W. Higgins 

 F. R. S. who was associated with Prof. Miller in the foregoing de- 

 scribed investigations, the author speaks more particularly respecting 

 the results arrived at in respect to the spectra of the fixed stars. He 

 says, " A single glance at the spectra afforded by Sirius, .Aldebaran, 

 and a Orionis, will show that the fixed stars have been created upon 

 the same general plan as our sun, and yet that to this unity of plan is 

 added variety of purpose in the different groupings of the elements 

 composing each. In Aldebaran, a Orionis, Capella, Arcturus and oth- 

 er stars, the sodium line of the solar spectrum is so clearly defined, that 

 the proof of the presence of this metal in the stellar atmospheres may 

 be considered as conclusive. Amongst some fifty stars observed, a very 

 large number, if not all, have lines coinciding with those proved to re- 

 sult from the presence of hydrogen. This would show that hydrogen 

 the element upon this earth, next to oxygen, perhaps, the most wide- 

 ly present, and equally essential with oxygen to the structure of every- 

 thing that has life is also verv widelv diffused through the universe. 



O *' i/ 



Magnesium and iron would seem to be present in a large number of 

 stars." 



Mr. Higgins and Prof. Miller considered the direct observation*of 

 the coincidence of stellar with metallic lines so important that they 

 intend not to rely upon measures, but to compare the metals directly 

 with the stars. This has already been done with some metals. Most 

 of the star spectra appear to be as full of lines as is the solar spectrum. 

 Other lines have been seen in Sirius, in the orange and in the green. 



If these distant suns have thus an analogous constitution with our 

 sun, may we not suppose that the planets, which, doubtless, they uphold 

 and energize, are of like material structure ? And if terrestrial ele- 

 ments, with their properties unchanged, be present, may we not fur- 

 ther surmise, that life in forms not wholly dissimilar to those on this 

 planet, and which these elements are so eminently adapted to subserve, 

 may not be wanting ? The spectrum of solar light reflected from the 

 planets has also been observed. Numerous lines have been measured 

 in the spectra of Venus, Jupiter, and the Moon. They have also been 

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