It is believed by experienced doctors that the heat which oozes out of the hand, on being applied to the sick, is highly salutary. It has often appeared, while I have been soothing my patients, as if there was a singular property in my hands to pull and draw away from the affected parts aches and diverse impurities, by laying my hand upon the place, and extending my fingers toward it. Thus it is known to some of the learned that health may be implanted in the sick by certain gestures, and by contact, as some diseases may be communicated from one to another.

Hippocrates