Students can see both continuous and line spectra with individual pieces of diffraction grating replica.  Apparatus uses incandescent source (with dimmer), neon, argon, and sodium sources.

A purposely simple apparatus shows that an electric discharge through a "rarified" gas produces visible light.

The Crookes tube apparatus shows the path of a stream of electrons in a rarified gas discharge.  The electron beam can be deflected with a common magnet.