278 



SCIENTIFIC THOUGHT. 



What might not these great minds have accomplished had 

 they attached the same importance to style and form as 

 most of the great French men of science, or had they been 

 called upon to teach a number of eager pupils, anxious, 

 not to take honours and degrees, but to understand and 

 further elaborate the suggestions of their master, as has 

 been the custom and tradition in Germany ? The history 

 of English science during the first half of the century 

 consists of a series of biographies, or of monographs on 

 single ideas and points of view. We are struck by the 

 individual greatness of the minds which produced them, 

 their originality or the suddenness of their appearance. 

 An 6loge by the permanent secretary of the Academy has 

 usually been considered sufficient to satisfy the historian 

 of science in France ; the life of every great philosopher 

 in Germany is identical with the history of a phase of 

 thought or with a school of research ; in England alone 

 the person of the thinker has nearly always claimed the 



by Miller in 1845 and by Foucault 

 in 1849 of observations relating to 

 this subject, had suggested in the 

 course of conversation that there is 

 a correspondence between emission 

 and absorption of the same kind of 

 light by the vibrating molecules of 

 the same body, according as it is 

 used as a source or a screen for 

 light. Had this idea of Stokes's, 

 which suggested the presence of 

 sodium in the atmosphere of the 

 sun, been followed out at the time, 

 the discovery of spectrum analysis 

 would have taken place ten years 

 earlier. Actually, the various pub- 

 lications, beginning with Fraun- 

 hofer's description of the dark lines 

 in the solar spectrum in 1814 and 

 proceeding through the observa- 

 tions of Herschel, Talbot, Drum- 



mond. Miller, Angstrom, Pliicker, 

 Swan, and Balfour Stewart on 

 the absorption and radiation of 

 heat, found their consummation 

 when Bunsen and KirchhofF settled 

 the main point in question viz., 

 "that the bright lines of an in- 

 candescent gaseous body depend on 

 the chemical constituents of the 

 same." Then at length spectrum 

 analysis became possible. See on 

 this matter Kirchhoff's own histori- 

 cal resunie of the year 1862, re- 

 printed in ' Gesammelte Abhand- 

 lungen ' (Leipzig, 1882), p. 625, 

 &c.; also Sir William Thomson's 

 'Baltimore Lectures,' shorthand 

 notes, 1884, p. 100, and Stokes's 

 translation of Kirchhoff's first paper 

 in 1860 ('Philos. Magazine,' March 

 1860). 



