16 Proceedings of the Royal Society oj Victoria. 



quent history of the ejected gases is disclosed to us by the 

 variations of the bright and dark line spectra, that of the main 

 body by the dying down of the continuous spectrum. These 

 combine to show that the star has throughout retained the 

 general character of an Orion — or at least of a Sirian — star, while 

 the mass of gas surrounding it now differs from an ordinary 

 nebula mainly in its state of aggregation. The exact relation 

 between the outbreak and the changes going on in Ritchey's 

 nebula is a problem for the future to solve. 



