XVII.] THE RESULT OF THE INQUIRY. 143 



Our lengthened consideration of this question has really led us to 

 a firm support not only of the dissociation hypothesis but of the meteo- 

 ritic hypothesis as well. 



As on the latter hypothesis the stars become hot in consequence 

 of meteoritic collisions, we should expect to find nebulous conditions 

 following suit ; seeing that nebulae are masses of meteorites, we should 

 expect to find especially the gaseous nebulae and results depending 

 upon their presence in the region where the hottest stars exist in 

 which dissociation has been studied. 



The planetary nebulae consist of streams of meteorites moving 

 generally in spirals or in circular paths. There iis no very great dis- 

 turbance; we get a bright line spectrum from them, and we know 

 they are practically limited to the Milky Way. We have found that 

 the bright-line stars are limited to the Milky Way ; they are simply 

 stars involved in nebulae. There again we get a connection between 

 the Milky Way and nebulae. The new stars are due to relatively 

 fixed nebulae driven into by moving nebulae comet fashion, and they 

 are also limited practically to the Milky Way ; there again we have 

 the nebulous touch. The nebulous regions, which Sir William 

 Herschel was the first to chronicle, are more prevalent near the Milky 

 Way than elsewhere. 



It will be seen that we have a strict association of nebulae, possible 

 dissociation conditions, and the hottest stars in which that dissociation 

 has been studied; and we are at length face to face with a simple 

 explanation of the close contiguity of these apparently very diverse 

 phenomena. 



