Ingredients: 2 liters distilled water, 50 milliliters hydrogen peroxide (3 percent concentration), 0.2 gram luminol, 4 grams sodium carbonate, 0.4 gram copper sulfate pentahydrate, 0.5 gram ammonium carbonate. You can order the chemicals online at Science Stuff.
In a medium-size mixing bowl(fig. 1), add the hydrogen peroxide to 1 liter of water.
In another bowl, dissolve the luminol, sodium carbonate, copper sulfate, and ammonium carbonate in the second liter of water.
Lay out a few sealable, clear containers — test tubes with stoppers or Nalgene bottles are good.
Pour in equal measures of each solution (fig. 2) — and watch with glee as it lights up (fig. 3). The hydrogen peroxide solution oxidizes the luminol, producing 3-amino phthalic acid. As its electrons settle to a more sedate quantum state, they emit photons at wavelengths between 430 and 470 nanometers — purplish blue.