xxiv 



instrument attached to the telescope it was possible not only readily to 

 divide the sodium line D into its two compartments, but to exhibit also 

 the nickel line which Kirchhoff had observed between them. The spectra 

 of the stars were now, in the first instance, compared approximately with 

 the superposed atmospheric spectrum already alluded to, for the purpose 

 of suggesting what metallic lines probably existed in the star under obser- 

 vation, and then were compared directly, by actual juxtaposition, with the 

 actual spectra of those metallic vapours which had been already suggested. 

 It seems impossible to conceive any process more rigidly or conscientiously 

 exact than that which Messrs. Huggins and Miller thus skilfully adopted ; 

 and here I maybe excused for repeating that the attainment of the ulti- 

 mate object of the research depended, not on any approximation, however 

 close, of the stellar with the metallic spectra, but on the certainty of their 

 absolute coincidence. In this way, during the space of two years and a quar- 

 ter, many of the midnight hours of these gentlemen were passed in the 

 scrupulous examination and measurement of the spectra of upwards of fifty 

 stars ; but in several instances the number of the fine dark lines, the in- 

 evitable indices (be it remembered) of the material constitution of these 

 distant worlds, were so numerous, that to measure and map them all the 

 labour of months would barely suffice. The physical result of all this 

 scrupulous and conscientious care was to discover the fact, or it may be to 

 confirm the suspicion, that those mysterious lights with which the firma- 

 ment is spangled are in strict reality worlds fashioned, in their material con- 

 stitution at least, not altogether differently from the fashion of the little 

 orb on which we live ; beyond the question of a doubt they are proved, by 

 the investigations of our medallists, to contain at least the hydrogen, the 

 sodium, the magnesium, the iron with which all terrestrial creatures are 

 so familiar." 



On Tuesday, May 14th, 1867, Miller commenced at the lloyal Insti- 

 tution a course of four lectures on " Spectrum Analysis, with its applica- 

 tions to x\stronomy." These lectures were reported in the ' Chemical 

 News/ under the revision of the author. Again, at the Meeting of the 

 British Association at Exeter in 1869, he gave a lecture on Spectrum Ana- 

 lysis to working men. This lecture was afterwards published in the 'Po- 

 pular Science Review' for October 1869. 



Miller was interested in the subject of water analysis, and, in conjunction 

 with Professors Graham and Hofmann, prepared a Report for the Govern- 

 ment " On the Chemical quality of the Supply of Water to the Metro- 

 polis." This was printed in 1851. At a later period he undertook an 

 investigation " On the combined Action of Air and Water on Lead," and 

 in 1865 gave a lecture before the Chemical Society "On some points in 

 the Analysis of Potable Waters." 



Quitting the subject of Miller's original work, we pass on to a brief 

 notice of the various services rendered by him to Science. He was on 

 the Council of the Royal Society during the years 1848-50 and 1855-57, 



