That the body offers considerable resistance to the passage of electrical currents is well known. And that much variation in this resistance exists in different individuals, and even in the same person at different times, was long ago demonstrated. This variability is known to be due in part to the use of currents of different strength, of electrodes of different sizes, to variations in the moisture or dryness of the skin, to the thickness of the skin, to the distance apart of the electrodes, etc. In making comparisons of the resistance in many persons much care must be taken to eliminate these various sources of error.
Very few observations upon persons in a pathological condition made with accuracy have been recorded. A year ago Charcot called attention to the fact that electrical resistance in the body was constantly lessened in Grave's disease and in certain cardiac affections, notably asystolism, (Gaz.