66 THE POPULAR SCIENCE MONTHLY. 



THE HISTORY OF A STAR. 



By J. NORMAN LOCKYEE. 



IT is now exactly thirty years since the world rang with one of 

 those discoveries which go down to the ages and at once in- 

 sure the names of the makers of them being inscribed upon the 

 muster-roll of the immortals. In the autumn of 1859, Kirchhoff 

 and Bunsen announced that at last a way had been found of 

 studying the chemical nature of bodies in space nay, more, that 

 they had already begun the work, and found that the sun, at all 

 events, was built up of matter identical with that of which the 

 earth is composed. 



In physical science in most cases a new discovery means that 

 by some new idea, new instrument, or some new and better use of 

 an old one, Nature has been wooed in some new way. In this case 

 it was a question of a new idea and an old instrument. The in- 

 strument was the spectroscope. 



It forms no part of my present purpose to deal either with the 

 principles involved in spectrum analysis or its history during the 

 period which has elapsed since 1859. The task I have set myself 

 in this article is a much more modest one. 



First, I wish to point out that during the thirty years the 

 method of work which Kirchhoff and Bunsen applied to the sun 

 has been applied to the whole host of heaven. By this I do not 

 mean that every star has been examined, but that many examples 

 of each great class nebula, comet, star, planet have been studied. 

 The same kind of information has been obtained with respect to 

 these bodies as Kirchhoff and Bunsen gleaned with regard to the 

 sun ; and the great generalization to which I have referred has 

 been found to hold good in the main for all. From nebulae and 

 stars existing in space in regions so remote that the observations 

 have been of the utmost difficulty in consequence of the feeble- 

 ness of their light; from comets careering through stretches of 

 space almost at our doors, the same story has come of substances 

 existing in them which are familiar to us here. In ascending 

 thus from the particular to the general, from the sun to the most 

 distant worlds, it is obvious that the field of observation has been 

 enormously extended. Kirchhoff and Bunsen's view has been 

 abundantly verified, as we have seen ; but the question remains, 

 Has this larger area of observation supplied us with facts which 

 enable us to make a more general statement than theirs ? It is 

 possible that it has. Recent inquiry has suggested that if the 

 study of meteorites be conjoined with that of the heavenly bodies, 

 the story told by the spectroscope enables us to go a step further, 



