390 THE CANADIAN NATURALIST. [Vol. VU 



more powerful than the others to make aud destroy the chemical 

 combinatious. are knowa beyond the violet. All the forces 

 which manifest themselves on the surface of our globe, as 

 heat, light, and chemical energy, are sent to us in a ray of white 

 light. 



But this brilliant spectrum is not continuous. Fraunhofer has 

 discovered in it an infinity of black lines cutting the shining band ; 

 these are the '' dark lines " of the spectrum, and Kirchhofi" has 

 found that a certain number of them occupy the same position 

 as the '' bright lines " which occur in the spectra of metallic sub- 

 stances when in a state of incandescence. This last physicist, 

 generalising an observation of Foucault, has seen further that 

 under given circumstances these bright lines can be obscured 

 and " reversed," coinciding then with the dark lines of the solar 

 spectrum. 



We have been able to conclude that these have an identical 

 origin and are due to radiations given off by metallic substances 

 spread in vapour over the solar globe, radiations which are obscured 

 by these same vapours in the atmosphere of the sun. Thus the 

 star which gives us heat, light, and life, is formed of elements 

 like those which form our globe. These elements are hydrogen 

 and metals in a state of vapour. They are not distributed 

 equally in the mass of the sun and in his rarefied envelopes ; the 

 hydrogen and most volatile metals are raised to a greater height 

 on the surface of the sun than are the other metals. They are 

 never in repose ; this ocean of incandescent gas is continually 

 agitated by tremendous tempests. The tromhes throw themselves 

 out in immense columns to the height of 50,000 leagues above 

 the gaseous sphere; these are the ''protuberances," and they 

 shine with a rose light peculiar to themselves ; and they are 

 formed, according to Jansen and Lockyer, by hydrogen, very 

 rarefied, and also by an unknown substance — "helium." The 

 luminous globe itself, the photosphere, gives the spectra of 

 our ordinary metals, except gold, silver, platinum, and mercury ; 

 the precious metals, those which have little affinity for oxygen, 

 being wanting. But, on the contrary, in the solar spectrum there 

 are "lines" different from those which the metals of our earth 

 give, but which are like them. The lines of the metalloids are 

 wanting, as are the lines which are characteristic of compound 

 bodies. The gaseous mass has such an incandescence that no 

 chemical combination could withstand it. 



