Effect:
A volunteer from the audience is asked to shake a closed bottle that contains a clear colourless liquid. The solution becomes blue and the volunteer returns to his/her seat. After several minutes, the solution fades to colourless. The volunteer is called back to the front to reshake the bottle. The contents turn blue again. This cycle can be repeated every several minutes through out the show.

What You Need:
- 1 L clear screw cap bottle
- water
- potassium hydroxide
- dextrose
- a few crystals of methylene blue
- gloves

What You Do Before the Show:
- Before the show dissolve 13 g potassium hydroxide and 10 g dextrose in 500 mL water already placed in the bottle.
- Add only a few small crystals of the methylene blue. It is important not to add too much.
- Shake the sealed flask to dissolve the methylene blue. You should get a blue solution. After several minutes, it should go clear or perhaps a very pale yellow.
- You can now put the bottle on your stage.

What You Do During the Show:
- See Patter.

What is Happening:
- In its oxidized state in solution, methylene blue is blue.
- In the presence of a a reducing sugar and potassium hydroxide, the methylene blue is converted to a colourless reduced form.
- Shaking the flask causes dissolved oxygen to convert the methylene blue from a colourless form to the blue form.
- This cycle can be repeated many times.

Hazards:
- Potassium hydroxide is a corrosive substance.
- Give a pair of gloves to the volunteer just in case the bottle might leak.
- Have the volunteer hold the bottle securely at the bottom and top.

Patter:
- The Wizard is always looking for apprentices to learn how to become a Wizard.
- After explaining this, ask for volunteers. You'll likely get plenty.
- Have the volunteer put on the gloves and then shake the bottle. - After the solution turns blue, congratulate the volunteer for passing the first hurdle toward becoming a Wizard.
- While you have the volunteer take a bow, have the audience applaud this effort.
- Privately tell the volunteer to keep the gloves on because they will be back (don't tell why).
- As you proceed to the next trick, the flask contents will go colourless. The audience will probably not notice since all their attention should be on YOU!
- At the end of your next trick draw the audience's attention to the bottle.
- Tell the volunteer that they must not have done a very good job and they'd better try again.
- Before they do, tell him/her that we have to take back the congratulations and have the audience unclap (hands together and quickly pull apart; repeat several times).
- Have the volunteer shake the bottle.
- This cycle of getting the volunteer back can be repeated several times through out the show.