I haven't read very much about experiments in psychic healing, although I know that many such experiments have been carried out, and quite a few have obtained positive results. In his recent book The End of Materialism, veteran parapsychologist Charles T. Tart describes one such experiment, which was performed back in 1965. The experimenter was a biologist named Bernard Grad, a professor at McGill University.
Tart tells us, "Grad was a cancer researcher who got interested in psychic healing, especially when he met an immigrant to Canada, Oskar Estabany, who had a reputation as a healer." Estabany would lay his hands on his patients — both human and animal — and apparently accelerate the healing process. Grad's question was whether the healing was accomplished by some psychic mechanism or simply by the emotional benefits of Estabany's soothing touch. To answer this question, he designed experiments intended to isolate the psychic mechanism, if any.
Tart continues:
Grad carried out two classic studies (1965), one in which the "patients" were wounded barley seeds, the other in which the "patients" were wounded laboratory mice. Let's look at the latter.
The laboratory mice were deliberately wounded by having a fold of their inherently loose skin plucked up and then a small chunk cut off with scissors. This produced a skin wound, which was a useful kind of illness to work with experimentally, because the size of the wound could be precisely measured by putting a piece of tracing paper over it and outlining the edges of the wound. Then a device called a planimeter could be used to objectively measure the actual area of the wound. Forty-eight mice were thus wounded and randomly assigned to three groups….
Aside from mental suggestion when people are the patients, we might conventionally hypothesize that the laying-on-of-hands healing might also involve some kind of chemicals emitted through the healer's skin, chemicals that might have a healing effect. This would be useful to discover if it were indeed the case for some healers, but Grad wanted to isolate his mice patients from anything but a psi healing effect. Thus each mouse received an individual treatment, but to prepare for the treatment, a research assistant (who didn't know what group the mice were to be in) would take a mouse from its cage, put it into a paper bag, and staple it shut so that the mouse was no longer handled directly. Few chemicals can readily penetrate a layer of dry paper in a short time.
Maybe just being put in a paper bag has an effect on a mouse? But all three groups of mice were put into paper bags.
For the experimental group, Estabany would then come in and hold the bagged mouse in the palms of his hands for twenty minutes twice a day, while visualizing the flow of healing energy. When done, Estabany would leave the room, and then a research assistant would come it and put the mouse back in its cage, released from its paper bag. In the control group, once the mouse had been bagged, it sat on a shelf for the same amount of time Estabany gave healing treatments to the experimental mice. This controlled for being bagged per se.
The possibility also existed that the warmth of the healer's hands could be responsible for promoting healing, so in the third, "heat control" group, another assistant, not known to have any healing abilities, held the bagged mouse for the same length of time.
Grad had decided in advance that the degree of healing of the wounds, measured by how much they had closed up, would be measured after two weeks. The statistical analysis of areas showed significant differences. It's pretty clear even from a second set of wound tracings that the controls and heat controls showed similar, moderate degrees of wound healing, but the experimental group treated by Estabany showed far more healing. [pp. 170-173]
Tart's book reproduces charts showing the wounds before and after psychic healing. It is obvious even to the naked eye that the healer-treated wounds fared much better. Of these 14 wounds, fully ten have been reduced to the size of a pinprick, while the remaining four are slightly larger but still much improved. By contrast, both the regular control wounds and the heat-control wounds are noticeably larger. Of these 28 wounds, only one is the size of a pinprick, and many of the others are two or even three times larger than the largest of the healer-treated wounds. Naturally, Grad didn't just eyeball the results; he relied on planimeter measurements to determine the exact area of each wound.
Note the care taken by Grad to address possible objections to the experiment. The mice were bagged so that chemicals from human skin would not affect them. Even the control mice were bagged. One set of control mice was exposed to the heat of human hands. It is hard to imagine how the experiment could have been more elegantly designed.
Tart goes on to describe Grad's barley seed experiment, which was equally well designed and equally successful.
More on Grad's work can be found in this Google Books entry and in this one (which includes discussion of a much larger follow-up study with 300 mice, also with positive results).