ABSTRACT
Huggins, William I looked into the spectroscope. No spectrum such as I expected! A single bright line only!. . . The riddle of the nebulae was solved. The answer, which had come to us in the light itself, read: Not an aggregation of stars, but a luminous gas. Stars after the order of our own sun, and of the brighter stars, would give a different spectrum; the light of this nebula had clearly been emitted by a luminous gas.
