,j4 JN STARRY REALMS. 



Hows. It would appear that so long as the electricity ic 

 flowing through the glass tube its action on the gas is to 

 impart a very high temperature. It is in consequence of 

 this temperature that the gas glows. Now we can offer a 

 reasonable account of the luminosity of the Great Nebula 

 in Orion. The particles of gaseous or vaporous material 

 of which it is formed are of an extremely high tempera- 

 ture, sufficient to enable them to glow with the brilliancy 

 which renders them visible. 



It is now almost twenty years since a marvellous acces- 

 sion to our knowledge of such objects as the Great Nebula 

 in Orion was made by Sir William Huggins. I have used 

 hydrogen as an illustration in describing the character of 

 the nebula, but I have now to add that the presence of 

 hydrogen is no mere fiction but a substantial verity. Truly 

 we here open up one of the most marvellous chapters 

 which science has to disclose. The chemist can analyse 

 the different substances on the earth with his test tubes, 

 and he can tell the elements of which they are composed. 

 But in this old-fashioned chemistry it was at least reason- 

 able for the chemist to demand a portion of the substance 

 he was expected to analyse. Unless he were provided 

 with a sample, how could it be possible for him to grind 

 it up or submit it to the various operations of his labora- 

 tory ? In these modern days the chemist can perform 

 operations of which his predecessors never even dreamed. 

 No doubt the old method is still used nay, is indeed at this 

 moment cultivated with greater skill and means than in 

 any previous age but side by side with the old method, 

 and as an invaluable supplement thereto, the new method 

 of chemical research, called spectrum analysis, has been 



