COSMIC PHILOSOPHY 



such an apparently simple article as a child's 

 calico frock. He shows that the various sciences 

 by turns stand in the relation of arts to each 

 other ; and that often the mere process of ob- 

 servation in any one science requires the aid of 

 half a dozen other sciences. But it is needless 

 for me to go on quoting from an essay which 

 is easily accessible, and which should be read 

 from beginning to end by every one who wishes 

 to understand the true character of scientific 

 progress. I prefer to add an illustration or two, 

 suggested by the progress of science during the 

 nineteen years that have elapsed since that es- 

 say was published ; and to observe how Kirch- 

 hoff 's discoveries in spectrum analysis — ren- 

 dered possible only through a great advance in 

 chemical knowledge — have reacted upon as- 

 tronomy, enabling Mr. Huggins to determine 

 the proper motion of Sirius, and consequently, 

 by putting it in our power to ascertain the mo- 

 tions of all those stars which, moving directly 

 towards or away from us, yield no parallax, 

 have laid the foundations for a general theory of 

 sidereal dynamics, to be further elaborated in the 

 future. Or to take a still more striking instance, 

 let us remember how Adam Smith's elucidation 

 of the principle of " division of labour," in 

 sociology, suggested to Goethe the conception 

 of a " division of labour " in biology, and thus 

 heralded Von Baer's magnificent discovery that 

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