Many of us have seen spectrum tubes in action in science classes in the past. They are useful for viewing spectral lines of pure substances. You are going to need a decent power supply to light them up. The EISCO Spectrum Tube Power Supply has you covered. It can hold 26cm tubes securely in place.
The unit has shielded and spring-loaded tube sockets. It has a convenient on/off button for safety. You can use the power supply with spectrum tubes from Eisco and other brands. You will also need diffraction grating glasses.