1
The conditions in the outer strata should bear some resemblance to those existing in the gaseous nebula.
2
And the nebula in Draco 4373, seems to present an intermediate stage between the purely gaseous nebula and this one.
3
After the novae become fairly faint, the bright lines of the gaseous nebula spectrum are seen for the first time.
4
So it has come about that the picture of a hot gaseous nebula revolving as a unit body has given place to other pictures.
5
In other words, it is not wise to draw too fine a line between a gaseous nebula and one consisting of solid particles with gas.