Intelligence and Miscellaneous Articles. 399 



Thus a Geissler's tube has given, between the poles of an electro- 

 magnet, the ordinary spectrum of carburetted hydrogen, whereas, 

 without the intervention of magnetism, it gave the carbonic-oxide 

 spectrum without the lines of hydrogen being visible. 



In another tube, filled with hydrogen obtained by the decomposi- 

 tion of water and dried with sulphuric acid, which gave Pliicker's 

 two hydrogen-spectra, under the influence of magnetism there ap- 

 peared those sulphur-lines which M. Wiillner has regarded as form- 

 ing the hydrogen-spectrum No. 3, while the spectrum of carbonic 

 oxide was shown on the polar wires. 



It would doubtless be premature to endeavour to formulate a law 

 according to w r hich these changes take place ; but a positive fact is, 

 that they do not appear to introduce any new spectrum peculiar to 

 the action of the magnetic forces. — Comptes Rendus, August 7, 1871. 



ON THE TESTIMONY OF THE SPECTROSCOPE TO THE TRUTH OF 

 THE NEBULAR HYPOTHESIS. BY PROFESSOR DANIEL KIRK- 

 WOOD, OF BLOOMINGTON, INDIANA. 



In March 1846 the partial resolution of the great nebula in Orion 

 was announced by Lord Rosse. In September of the following 

 year the late Professor W. C. Bond, of Harvard University, stated, 

 in confirmation of this interesting discovery, that the part of the 

 nebula about the Trapezium " was resolved into bright points of 

 light " by the great refractor of Cambridge. " It should be borne 

 in mind," continued Professor Bond, " that this nebula and that of 

 Andromeda have been the last stronghold of the nebular theory — 

 that is, the idea, first thrown out by the elder Herschel, of masses 

 of nebulous matter in process of condensation into systems." 



These grand achievements were regarded by the majority of astro- 

 nomers as fatal to the claims of the nebular hypothesis. It is not 

 to be denied, however, that this celebrated theory has more than 

 recovered from the shock which it then received, that it has, in 

 fact, been materially strengthened by the researches and discoveries 

 of the last twenty years. The truth of this remark is strikingly ex- 

 emplified by the revelations of the spectroscope. The man who at 

 the middle of the nineteenth century would have been bold enough 

 to predict the discovery of the physical constitution of the heavenly 

 bodies, or the determination of the elements of which they are com- 

 posed, would have been generally deemed a scientific enthusiast. 

 This, however, and more than this, has been actually accomplished. 

 In the hands of Huggins, Secchi, Young, and others the spectro- 

 scope, that marvel of modern science, has yielded satisfactory testi- 

 mony, not only in regard to such stars as are reached by our unas- 

 sisted vision, but even respecting the telescopic nebulae, apparently 

 on the outskirts of the visible creation. A detailed account of these 

 wonderful achievements would not comport with our present pur- 

 pose. Such results, however, as bear directly upon the theory of 

 Laplace will be briefly noted. 



