Nebula N. G. C. 1499 Persei—after Roberts.
Nebula N. G. C. 6960 in Cygnus—after Ritchey.
Advanced spectroscopic means reveals that the spectra of these “white” nebulæ are not simply continuous. Thus that of the Andromeda nebula shows very faint dark lines crossing it, apparently accordant with those of the solar spectrum and faint bright ones falling near and probably coincident with those of the Wolf-Rayet stars, due to hydrogen, helium, and so forth. These later observations make practically certain what earlier ones permitted us just now only to infer: that it is not composed of stars, but of something subtler still; to wit, of meteorites. The reasoning is interesting, as showing that if one have hold of a true idea, the stars in their courses fight for him.
