388 Celestial Chemistry. 



of the solar spectrum, and hence of the chemical nature of the 

 atmosphere surrounding the sun's photosphere, is one of the 

 most striking examples of that mutual assistance and inter- 

 dependence of the sciences of which we were speaking. So 

 soon as Kirchhoff saw the significance of the discovery of the 

 reversal of the bright lines of metallic spectra by passing their 

 light through vapour of the same matter, he wrote : ' ' The 

 method of spectrum analysis not only offers a mode of detecting 

 with the greatest simplicity the presence of the smallest traces 

 of certain elements in terrestrial matter, but it also opens out 

 the investigation of an entirely untrodden field, stretching far 

 beyond the limits of the earth, or even of the solar system. For, 

 in order to examine the composition of luminous gas, we require 

 only to see it, and it is evident that the same mode of analysis 

 must be applicable to the atmosphere of the sun, and of the 

 brighter fixed stars." 



Brilliantly has this prediction been verified by his own 

 researches on the sun, and by the elaborate observations of Mr. 

 Huggins and Dr. Miller on the other heavenly bodies. Of 

 these latter researches, we now proceed to give some account. 



To the Intellectual Observer for June, 1863, Mr. Huggins 

 contributed a paper on the subject of " Spectrum Analysis 

 applied to the Stars," to which we would refer all readers of 

 the present article for the necessary introductory knowledge 

 of the subject, should they not already be possessed of such 

 elementary information. The valuable paper on " Spectroscope 

 Apparatus," in the November number of this Journal, may also be 

 usefully consulted. Gladly would we have left the subject to 

 be continued by the original discoverer of the results obtained, 

 but unfortunately Mr. Huggins cannot spare the necessary 

 time, and therefore the present writer, with his concurrence, 

 will endeavour to describe what has been done since the article 

 referred to was published. 



The great point of the paper of June, 1863, was 'to lay 

 before the readers of the Intellectual Observer an account 

 of the observations made by Mr. Huggins and Dr. W. A. Miller 

 upon the spectra of the Fixed Stars, including diagrams of 

 Sirius, Aldebaran, and Betelgeux, as presented to the Koyal 

 Society in a note dated February, 1863. Some few of the 

 lines in the diagrams there engraved had been ascertained by 

 measurement, but the greater number were due to eye estima- 

 tion ; and while certain metals, such as sodium, iron, and mag- 

 nesium, were almost certainly shewn to be present in certain 

 stars, the author stated that he and Dr. Miller considered the 

 direct observation of the coincidence of stellar lines with metallic 

 lines so important that they intended not to rely upon measures, 

 but to compare tho metals directly with the stars. 



