THE GREAT NEBULA IN ORION. 93 



The spectroscope had revealed much respecting the 

 constitution of the fixed stars. We had learned that they 

 are suns resembling our own. It remained only to 

 show that the Orion nebula consists of similar suns, in 

 order to establish beyond all possibility of doubt the 

 theories which had been so complacently accepted. A 

 very different result rewarded the attempt, however. 

 When Dr. Huggins turned his spectroscope towards the 

 great nebula, he saw, in place of a spectrum resembling 

 the sun s, three bright lines only ! A spectrum of this 

 sort indicates that the source of light is a luminous 

 gas, so that whatever the Orion nebula may be, it is 

 most certainly not a congeries of suns resembling our 

 own. 



It would be unwise to theorise at present on a result 

 so remarkable. Nor can we assert that Herschel s 

 speculations have been confirmed, though his general 

 reasoning has been abundantly justified. Astronomers 

 have yet to do much before they can interpret the 

 mysterious entity which adorns Orion s sword. On every 

 side, however, observations are being made which give 

 promise of the solution of this and kindred difficulties. 

 We have seen the light of comets analysed by the same 

 powerful instrument ; and we learn that the light from 

 the tail and coma is similar in quality (so far as obser 

 vation has yet extended) to that emitted from the 

 Orion nebula. We see, therefore, that in our own solar 

 system we have analogues of what has been revealed in 

 external space. I would not, indeed, go so far as to 

 assert that the Orion nebula is a nest of cometic 



