Incidentally, from here: http://www.faqs.org/faqs/skeptic-faq/
7.5: What is Kirlian Photography?
[Information from a posting by Dave Palmer <dpalmer@csulb.edu>]
The technique involves applying a high-frequency, high-voltage electrical source (such as from a Tesla coil) to a subject. The source is also very low-current, so the subject does not get electrocuted (it's the current in electricity that does the harm, not the voltage). When this is done, an "aura" of lightning-like electrical discharges forms around the subject. This field is visible to the naked eye (in a dark room, anyway), and may be photographed. Adherents of Kirlian photography claim that this field is some sort of "life energy" which may indicate things about the subject, such as health, psychic ability, and so forth. They claim that Kirlian photography sometimes shows the "phantom effect." That is, if a limb is amputated from the subject (or, less gruesomely, if a piece is torn off a leaf), that the field will still show the missing piece for a time, because its "life energy" is still there.
There is no truth to the claims that it shows any sort of "aura" or "life energy." It is merely a coronal discharge, complete with ozone production. The most damaging argument against the "life energy" claim is that Kirlian photography works on ANY subject that conducts electricity, even completely lifeless metal, or synthetic sponges soaked in salt water.
The field produced jumps around quite a bit. Because the shape of the field changes, it can occasionally appear to outline non-existent areas of the subject, hence the phantom effect. Dave Palmer reports producing the phantom effect with tin foil about as often with leaves. Far more often, he got false phantom effects, that is, pictures of pieces of the subject that had never existed.