404 THE POPULAR SCIENCE MONTHLY. 



But about the close of the last century, Bruno having guessed the 

 fundamental tact of the nebular hypothesis, and Kant having reasoned 

 out its foundation idea, Laplace developed it, showing the reason for 

 supposing that our own solar system, in its sun, planets, satellites, 

 with their various motions, distances, and magnitudes, is a natural 

 result of the diminisliing heat of a nebulous mass a result obeying 

 natural laws. 



There was an outcry at once against the "atheism" of the scheme. 

 The war raged fiercely. Laplace claimed that there were in the heav- 

 ens many nebulous patches yet in the gaseous form, and pointed them 

 out. He showed by laws of physics and mathematical demonstration 

 that his hypothesis accounted in a most striking manner for the great 

 body of facts, and, despite clamor, was gaining ground, when the 

 improved telescopes resolved some of the patches of nebulous matter 

 into multitudes of stars. 



The opponents of the nebular hypothesis were overjoyed. They 

 sang pseans to astronomy, because, as they said, it had proved the 

 truth of Scripture. 



They had jumped to the conclusion that all nebulae must be alike 

 that if some are made up of systems of stars all must be so made up ; 

 that none can be masses of attenuated gaseous matter, because some 

 are not. 



Science, for a time, halted. The accepted doctrine became this 

 that the only reason why all the nebulae are not resolved into distinct 

 stars is, because our telescopes are not sufficiently powerful. 



But in time came that wonderful discovery of the spectroscope 

 and spectrum analysis, and this was supplemented by Fraunhofer's 

 discovery that the spectrum of an ignited gaseous body is discontinu- 

 ous, with interrupting lines ; and this, in 184(3, by Draper's discovery 

 that the spectrum of an ignited solid is continuous, with no interrupt- 

 ing lines. And now the spectroscope was turned upon the nebulae 

 and about one-third of them were found to be gaseous. 



Again the nebular hypothesis comes forth stronger than ever. The 

 beautiful experiment of Plateau on the rotation of a fluid globe comes 

 in to strengthen if not to confirm it. But what was likely to be lost 

 in this ? Simply a poor conception of the universe. What to be 

 gained ? A far more worthy idea of that vast power which works in 

 the universe, in all things by law, and in none by caprice.' 



' For Bruno's conjecture (in 1591), see Jevons, vol. ii., p. 299. For Kant's part in 

 the nebular hypothesis, sec Lange, " Gcschichte des Materialismus," vol. i., p. 266. For 

 value of Plateau's beautiful experiment very cautiously estimated, see W. Stanley Jevons, 

 " Principles of Science," London, 1874, vol. ii., p. 36. Also Elisee Reclus, "The Earth," 

 translated by Woodward, vol. i., pp. 14-18, for an estimate still more careful. For a 

 general account of discoveries of nature of nebulaj by spectroscope, see Draper, ' Conflict 

 between Religion and Science." For a careful discussion regarding the spectra of solid, 

 liquid, and gaseous bodies, see Schellen, " Spectrum Analysis," pp. 100, et seq. For a very 

 thorough discussion of the bearings of discoveries made by spectrum analysis upon the 



