This is a summary of a talk given at the 1992 Skeptics conference by Dr Eric Geiringer.
[An E-meter is a device used by members of the Church of Scientology, and some related groups or individuals, to “diagnose” illnesses. The subject grasps a pair of metal electrodes connected to an Ohm-meter, and an “auditor” asks questions and interprets the meter’s readings.]
The resistance the skin offers to the passage of an electric current is inversely proportional to the amount of electrolyte in the neighbourhood, and that essentially means sodium chloride in the sweat.
The skin is an important regulator of the sodium chloride content of the tissues, which must remain constant within narrow limits.
The amount of sweat and its salt concentration (0.1-0.37%) will vary in different people and at different times in the same person with:
- fluid intake
- stage of menstrual cycle
- amount of salt in the tissues
- amount of salt in food
- the circum-ambient temperature
- the number of sweat glands
- their topical distribution
- adrenal activity
- anterior pituitary activity
- posterior pituitary activity
- hormone output of heart muscle
- kidney function
and a number of other factors, all playing a part at any given moment in determining how much salt will meet the electrodes.
To this must be added the psychic state of the subject at the time of measurement, because as with blushing (which is also part of the hypothalamic heat regulating mechanism) sweating will be brought on by joy, fear, embarrassment or pain.
The effect of these variables on the final reading is, of course, additive and gives a composite reading of little, if any, specific value.
E-meter operators may claim that the refinements which they have introduced into the machine and the method standardise subjects to all these variables, and can therefore isolate idiosyncratic differences and enable specific physical or mental disorders to be diagnosed, but it would be up to them to substantiate such an extraordinary claim.
Although Scientology in toto is a dangerous, exploitative and mischievous humbug, we must concede that, by recording and utilising psychic sweating to loaded questions, their use of the E-meter is on a par with the use of lie-detectors<|>–<|>i.e. a crude, nonspecific but marginally valid means of spotting emotionally sensitive areas in a significant number of subjects.
It is the imaginative use, or pretended use, of these Ohm-meters and Volt-meters to diagnose specific mental or physical disorders by homeopaths and acupuncturists which constitutes their real danger.