486 POPULAR SCIENCE MONTHLY. 



naturally developed society is a second corollary from the same law. 

 Of profound significance for the sociologist, however, is the fact that 

 to-day we are rapidly passing from such natural organization to a 

 new and highly artificial one. Problems of city life confront us on 

 every side. They are not devoid of ethnic importance ; investigation 

 is concentrating upon them. In the final paper of our series we shall 

 proceed to their consideration. 



SCIENTIFIC PROGRESS IN THE CLOSING CENTURY.* 



By PBor. LUDWIG BttCHNER. 



CENTURY of enlightenment century of science century of 

 reconciliation as such respectively may be characterized the 

 eighteenth, the nineteenth, and the twentieth centuries; though 

 in so characterizing the last we have somewhat forestalled time. 

 But the designation of the present century as that of science can 

 hardly be disputed; for progress in human knowledge and in con- 

 sequent power has been so great and far-reaching in this century, 

 and so rapid within the last few years, that in this respect no preced- 

 ing century can at all compare with this. 



Astronomy. It is known that Copernicus, fearing clerical per- 

 secution, was compelled to hold back his great work on the revolu- 

 tions of the heavenly bodies for thirty years, and that when finally 

 published it was condemned and prohibited as heretical. The tele- 

 scope also was put under the ban, because, according to the view 

 of the Church, it permitted men to see farther than God by the 

 structure of the human eye intended them to see. Nevertheless, 

 it was the telescope that put a definite end to the narrow notions 

 arising from the geocentric error, and ousted the earth and its in- 

 habitants from their imagined high place as center of the universe. 

 But the crowning of the astronomical edifice founded on these dis- 

 coveries occurred only in the century at whose exit we are stand- 

 ing, and this through the founding of the important science of astro- 

 physics and the knowledge acquired thereby of the chemical and 

 physical constitution of the heavenly bodies by which we are sur- 

 rounded. These researches were initiated by the wonderful dis- 

 covery made in 1859 by KirchhofT and Bunsen of the spectral analy- 

 sis or the language of light, which has furnished special elucidation 

 of the chemico-physical constitution of the sun, which elucidation 

 must have appeared impossible to previous science. Spectrum 



* From Prof. Ludwig Biichner's book, Am Todtenbett des Jahrhunderts, which is about 

 to be published in Germany. 



