ID: 
1840
Maker's Name: 
Philips
Where made: 
Other
Dimensions: 
39 × 9.5 × 21 cm

Each tube in the box of five tubes has a different gas or vapour. Each is a discharge tube, and contains Helium, Mercury, Neon, or Argon. They all would have screwed into the same high voltage supply unit.

Each will produce a spectrum with characteristic 'lines' - isolated wavelengths where emission is very strong.

One tube is marked 'unknown' so the set was probably used in a teaching lab experiment where students had to identify the unknown gas by comparing its spectrum with known standards.

Astronomers use the same technique to determine the compositions of distant stars.