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Flames are neutral plasmas (gases with the atoms or molecules lacking some electrons, but the electrons are still in the neighborhood). The glowing part of the flame is made of positive ions. It is surrounded by a "bath" of electrons. The electrons must not be completely free or else flames would exhibit large electrostatic effects. However, a simple experiment can be carried out to show that the electrons are not completely bound to the plasma either. If the flame from a candle is placed near a positively charged body, it will initially deflect away. After a short time, the flame will right itself and only respond to the effect of the body on the gas flow. The initial behavior is a result of the like charge repulsion. What is not seen directly is the attraction of the electrons in the plasma toward the positive body. These attracted electrons neutralize the charged body and allow the flame to relax.

A more dramatic effect is seen if a Whimhurst or Van de Graff generator is used, as these devices constantly replenish the charge on the body. Here, depending on how you set up the generator, the flame will either be constantly repelled or attracted. If you place the flame between the charged head and a grounding rod, you can see sparking between the two bodies through the flame, even if the distance is too large for sparking without the flame.

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