The D’Arsonval Galvanometer was invented in the 19th century by the esteemed French scientist Jacques D’Arsonval (1851-1940)

(Note: This is an excerpt from the book we’re writing on Scientology.)

Very little was known about electricity in the 18^th century. The subject commanded wide scientific and public interest. The idea that the human body was somehow electrical in nature was a matter of speculation and skepticism. The idea that God’s creation needed electricity when God had breathed life into Adam and Eve was an affront to clerics. God was the source of life and did not need electricity – whatever electricity was altogether – to animate God’s living Creation. God was the source of Life argued Christian theologians. Therefore, the Life Force was the Holy Spirit which pervaded all things as a function of God’s omnipresence.

Religion would soon suffer an even larger challenge from Science when Charles Darwin theorized that all natural species had evolved from lower forms. Naturalistic Evolution shook the core religious foundation of Divine Creation. Understood from this perspective, the earlier discovery that the human body, and indeed all biological organisms, were electrical in nature became part of the scientific foundation for Darwin’s 1859 revolutionary work On the Origin of Species.

In simplified terms, Evolution is driven by the electrochemical processes inherent in biology interacting with, and adapting to, the demands and challenges of the naturalistic environment. That the electrical properties of the human body and all organisms could be detected and measured represented a major scientific breakthrough that helped to explain, in part, the evolutionary process. As with all scientific breakthroughs, however, charlatans and their various schools of pseudoscience quickly appeared on the scene in hopes of gaining money and fame.

EARLY SCIENCE VS. EARLY PSEUDOSCIENCE

We begin our essay by contrasting the 18^th century work of Luigi Galvani and Franz Mesmer in order to show the differences between science and pseudoscience as concerned early investigations into electricity and the human body.

Luigi Galvani (1737-1798) was an Italian scientist whose work demonstrated that very small electrical currents caused nerve and muscle function. In what would become a very famous experiment he conducted on September 20, 1786, Galvani applied a small external electrical current to the leg of a dead frog and observed the subsequent contraction of the muscles in the leg of the frog. Galvani was working based upon his theory that a “neuro-electric” fluid was present in the nervous systems of animals — including humans. His experiment seemed to confirm this, and Galvani became known as the father of “animal electricity.”

To say that Galvani’s experiment attracted attention is an understatement. Rather, his experiment created an overnight sensation. In his fascinating essay published at aeon.co, Professor Iwan Rhys Morus writes:

In 1803, Giovanni Aldini (Galvani’s nephew) visited London to defend animal electricity against its detractors. At one performance he electrified a decapitated dog, with the Prince Regent in the audience. As the climax of his visit he carried out galvanic experiments at the Royal College of Surgeons on the body of a man named George Forster, just hanged for murder. It was a gruesome affair: ‘The jaw of the deceased criminal began to quiver, the adjoining muscles were horribly contorted, and one eye was actually opened.’ Aldini was lampooned in the anti-radical press as just another buffoon trying to con the public that electricity was life. But even amongst the relatively staid fellowship of the Royal Society, Aldini had plenty of supporters. He was sponsored by the Royal Humane Society who thought his experiments offered a way of bringing drowned sailors back to life.

Mary Shelley certainly knew about Aldini’s experiments when she wrote Frankenstein. Discussions about electricity, the soul and the possibilities of artificial life were common currency in the literary and political circles in which she and her husband moved. In 1818, the year Frankenstein was published, another electrical resurrection was attempted in Glasgow, this time on the body of a convicted murderer called Matthew Clydesdale. The experiments were carried out by doctor Andrew Ure, who waxed dramatically on how electricity turned the dead man’s body into an automaton: ‘Every muscle in his countenance was simultaneously thrown into fearful action: rage, horror, despair, anguish, and ghastly smiles, united their hideous expression in the murderer’s face.’

As in any emergent field of research, there were alternative schools of thought in the 18^th and 19^th century concerning the animating force of living things. Animal electricity therefore became linked to the idea of vitalism. Vitalism held that all living things contained an innate vital energy. Johann Friedrich Blumenbach (1752–1840) called this energy “élan vital” (vital force).

FRANZ MESMER, MESMERISM, AND ANIMAL MAGNETISM

Franz Mesmer (1734-1815) posited the theory that animal magnetism – as opposed to animal electricity — was the animating force of the body. Mesmer maintained that diseases occurred in humans when the flow of animal magnetism became disrupted or blocked by injury, structural defects, etc. Mesmer treated people by using his hands and eyes to balance the energy flows in his patients. Mesmer also taught others his techniques. Mesmerism was a predecessor to the New Age notion of balancing chakras and energies in the body. Mesmerism is also evocative of the ancient Chinese therapy of correcting the flow of Chi, or Qi, in the meridians of the body by use of acupuncture and herbs.

Mesmerism was in vogue for about seventy-five years. The technique itself made Mesmer a fortune as he had a lucrative practice in a wealthy section of Paris. Like L. Ron Hubbard, Mesmer had his critics who dismissed him as a charlatan and his work as quackery.

Mesmerism generated such notoriety and controversy that King Louis XVI appointed a royal committee in 1784 to investigate the subject. Committee members included Benjamin Franklin who was then serving as the American ambassador to France. Also serving on the committee was Dr. Joseph-Ignace Guillotin who, although he did not invent the guillotine, had his name appropriated for the device after having recommended it as a more humane and precision form of execution than beheading people by the use of a sword or an axe. In one of those odd historical coincidences, King Louis XVI, who had appointed Dr. Guillotin to the Mesmerism investigation, would lose his own head to the guillotine on January 21, 1793 following the French Revolution and the abolition of the monarchy. King Louis XVI’s wife Marie Antoinette would suffer the same fate.

The Mesmerism Commission, with one dissenting vote, determined that Mesmer had not discovered any sort of new physical fluid and that Mesmerism’s claimed results were largely the result of the imaginations of those who had been treated. This is a fascinating foreshadowing of the same charges and conclusions leveled by critics against L. Ron Hubbard.

Although the precise details were not understood at the time, the work of Galvani scientifically demonstrated that electrical activity was present in in animal and human bodies. On the other hand, Franz Mesmer, who was a medical doctor, interpreted the existing scientific research of his day to create his popular, if dubious, science of animal magnetism. As L. Ron Hubbard would later do, Mesmer claimed that his science could cure disease and optimize one’s physical and mental health. And like Hubbard, Mesmer’s work received widespread coverage in the media of his day and was criticized by many and attracted the attention of the authorities.

ELECTRICAL MEASUREMENT DEVICES

Unlike Mesmerism, which was conducted by the hands of the practitioner, there was a need for physical hardware that could be used to conduct real world electrical research. At the time, electricity was still confined to laboratories; the practical means of large-scale electrical generation and transmission to the masses was still decades away. In order to even invent new electrical devices, then, there was a great need for equipment that could be used to measure various electrical properties in laboratories. Hence, the invention of electrical measurement devices necessarily preceded the large-scale implementation of electricity.

Some of the most important research in this era focused around electrical conductance and electrical resistance. For example, if electricity was to become practical and usable on a wide scale then researchers, scientists, and inventors needed to discover those materials through which electricity would most easily flow. Materials such as copper became known as conductors because they have very little resistance to the flow of electricity and thus easily conduct electricity. Conversely, it became necessary at times to inhibit the flow of electricity in circuits. Materials needed to be discovered that had a very high resistance to electricity. Materials that resist the flow of electricity became known as resistors.

The question of knowing how to measure resistance and conductance became important. In 1827 the German scientist George Ohm (1789-1854) described the mathematical basis of how to measure electrical resistance and his work became known as Ohm’s law. Electrical resistance is measured in “ohms” after the work of Ohm. Conversely, an international convention in 1881 agreed to measure electrical conductance by using a unit of measure it named the “siemens” in honor of the German industrialist and inventor Ernst Werner Siemens (1816-1892). A capital S is used to denote siemens.

In order to measure electrical resistance as mathematically described by Ohm’s law, a physical device was needed. The first such primitive device was invented by André-Marie Ampère (1775-1836) and was based upon the 1820 description of the Danish physicist Hans Christian Ørsted (1777-1851). Ørsted was the first scientist to discover that an electric current created a magnetic field; his work established the early crucial relationship between electricity and magnetism.

Ampère named his new device the “galvanometer” in honor of Luigi Galvani. A series of improved galvanometers was invented over time. For the researcher to visually read the measured resistance, galvanometers featured a pointer, or a needle. The pointer would make a rotary motion and deflect to the left or right of center depending upon the input from the electrodes on the patient. The needle swept across a curved analog dial that was divided into units of measurement akin to a ruler. A photo of the 19^th century D’Arsonval galvanometer which appears at the top of this article. The photo shows us the arrangement of the pointer and an analog scale.

ELECTROPHYSIOLOGY: THE GALVANOMETER MEETS THE HUMAN NERVOUS SYSTEM

Hermann von Helmholtz (1821-1894) is considered the originator of the field of electrophysiology. This field uses various measurement devices, low level electrical current, electrodes, and sensors to measure physiological processes such as the speed of nerve impulses, cardiac rhythm, respiration, and so on. One modern example of electrophysiology is the use of an EKG (electrocardiogram) machine to detect and measure cardiac rhythm.

From the late 1840’s forward, Helmholtz conducted a series of experiments which included the use of a galvanometer. His experiments sought to determine the speed of nerve transmission in humans. Helmholtz described his technique:

In a human being, a very weak electric shock is applied to a limited space of skin. When he feels the shock, he is asked to carry out a specific movement with the hand or the teeth, interrupting the time measurement as soon as possible.

Helmholtz’s experiments on the speed of human response to stimuli ended the long-held belief that nerve impulses were instantaneous and therefore immeasurable. Helmholtz’s work showed that skin, muscles and nerves were electrically active. His work also demonstrated that this electrical activity could be measured using a galvanometer. Henning Schmidgen, a research scholar at the Max Planck Institute, summarized Helmholtz’s 1850 research (emphasis mine):

Helmholtz concluded that in humans, the ‘message of an impression’ propagates itself ‘to the brain with a speed of circa 60 Meter (180 feet) [per second] and does not differ noticeably at various times. Helmholtz also reasoned that the time needed ‘by the brain for the processes of perceiving and willing’ was 0.1 seconds. He had to admit, however, that his experiments with humans involved a factor apt to threaten the required constancy of all others, namely the attention of the subject under experimentation. ‘Slight feelings of sickness’ and ‘fatigue’ of the experimental subject could significantly disturb the precision measurements, as well as distractions of all kinds: ‘If at the time of perceiving the signal the thoughts are occupied with something else, and if the mind has to recall to itself what kind of movement one must carry out, it [the reaction] takes much more time.’ At this point, Helmholtz had definitely reached psychological ground.

Schmidgen’s observation that Helmholtz had taken the galvanometer into psychological ground is important as it shows the historical point at which the galvanometer became a psychogalvanometer. Helmholtz noticed, but could not explain why, the speed of nerve impulses slowed down in people who were distracted or preoccupied. This was a matter where it was uncertain if correlation implied causation.

Helmholtz and other experimenters observed decreases in skin resistance in response to stressors, distractions, and external stimuli. Said another way, researchers were observing an increase in the electrical conductance of the skin. This characteristic came to be called by various names such as Galvanic Skin Response (GSR), the Psychogalvanic Reflex and so forth.

Because Galvanic Skin Resistance is characterized by an increase in the electrical conductance of the skin it is measured in microsiemens (μS). In 1967, the “Galvanic Skin Response” and other related terms were subsumed into the more precise term Electrodermal Activity (EDA). The human skin is micro-electrical in nature, has both active and passive micro-electrical characteristics, and the electrical resistance and conductance of the skin is constantly changing. The field concerned with measuring the electrical activities of the skin is called electrophysiology

Writing in the journal European Polygraph (2015, Volume 9, Number 4), Jan Widacki offers a brief overview of the galvanometer as used in 19^th and early 20^th century neurological and psychological research:

Charles Féré (1852–1907) found that by passing a low electrical current between two electrodes placed on the surface on the skin, one could use a galvanometer to measure momentary decreases in skin resistance in response to a variety of stimuli of various types, including visual and auditory ones (Féré 1888). In this way Féré discovered that the skin becomes a better conductor of electricity in the presence of external stimuli.

The needle, or pointer, on Féré’s galvanometer explained Helmholtz’s earlier observation: Momentary decreases in skin resistance occurred “in response to a variety of stimuli of various types, including visual and auditory ones.”

PSYCHOLOGISTS AND LAW ENFORCEMENT EXPERIMENT WITH THE GALVANOMETER

The correlation between psychological states and changes in electrical skin resistance was established by Féré and other researchers. This discovery had many implications. For example, in their paper published in the journal The Association of Psychological Science, authors Nick Joyce and David Baker commented on some of the historical usages of the galvanometer in medicine, psychology, and law enforcement:

…In 1901, Willem Einthoven (1860–1927) devised a very powerful device called a string galvanometer. This version of the galvanometer was so sensitive that it was used to measure the electrical potentials of the heart from outside the body, producing the electrocardiogram.

Not to be left out of the game, psychologists began to investigate the influence of electricity in psychological phenomena.

One such early use of the galvanometer was in research published in 1890 by Jean De Tarchanoff (1857–1927) in Russia entitled “Galvanic Phenomena in the Human Skin in Connection with Irritation of the Sensory Organs and with Various Forms of Psychic Activity.”  It related to emotional responses to stress and sensory stimuli recorded as changes in the electrical properties of the skin on a galvanometer. The name Tarchanoff phenomenon was given to the effect….

HUMAN SWEAT GLANDS

The psychogalvanometer works because it can measure changes in the electrical resistance of human sweat glands changes in response to external stimuli.

Why and how does electrical resistance occur in human sweat glands?

A brief explanation tells us why. There are three main types of sweat glands in the human body: The apocrine, the eccrine, and the apoeccrine. The apoeccrine sweat glands have characteristics of the both the apocrine and the eccrine sweat glands. There are other specialized sweat glands, but they are not of interest to the discussion at hand.

The apocrine sweat glands secrete fluid into the sacs of hair follicles. The apocrine sweat glands do not pertain to our discussion. What we are interested in are the eccrine sweat glands. The eccrine sweat glands are very numerous in the body. While estimates vary, there are two to four million eccrine sweat glands depending upon the size of an individual human body. The eccrine glands secrete sweat onto virtually the entire surface area of the human body.

The eccrine sweat glands are controlled by the body’s sympathetic nervous system. When the body is hot, the sympathetic nervous system tells the eccrine sweat glands to secrete sweat in order to help cool the body; sweat evaporates and takes heat away from the body.

The eccrine sweat glands are part of the thermoregulation system of the body. For example, when you exercise vigorously and get hot the eccrine sweat glands secrete sweat at prodigious rates. Depending upon factors such as ambient temperature, body mass, and the intensity of exercise, a healthy person can sweat between 0.8 to 1.4 liters (roughly 27.4 to 47.3 oz.) during one hour of exercise. Even more sweat can be produced during extreme athletic activities.

Eccrine sweat glands are especially dense on the palms of the hands and the soles of the feet. Of interest to our discussion is the fact that the eccrine sweat glands in the palms of the hands and the soles of our feet sweat primarily in response to psychological stress. If you’ve ever been extremely nervous or stressed, you likely experienced sweaty palms and sweaty feet. This happens because the sympathetic nervous system triggers these sweat glands in response to stress. These stress-triggered “sweat events” trigger changes the electrical resistance of your skin. For this reason, the electrodes of psychogalvanometer work best when attached the hands or the soles of the feet where the eccrine sweat glands are more heavily concentrated.

LIE DETECTION

Because the palms and feet sweat during time of stress, interest in the psychogalvanometer as a lie detector became of interest to law enforcement and private investigators in the early 20^th century. The February 1937 edition of Modern Mechanix magazine covered the story of priest-psychologist Father Walter G. Summers and his “practically infallible” psychogalvanometer when used as a lie detector. The author of this piece is unknown:

Research in the early 20^th century showed that galvanic skin response alone was not adequate for use as a lie detector. Hence, additional biometric channels were added to measure respiration, heart rate, and blood pressure. Because the lie detector evolved into measuring many channels, it became known as the polygraph, where poly + graph refer to the styli of the device recording many channels on a continuous sheet of graph paper. In the photo of Father Summers’ lie detector shown above, we see only one channel recorded on the graph paper. This is the galvanic skin response channel. Modern polygraphs record three or four channels as we see on this graph paper:

PATENTS FOR PSYCHOGALVONMETERS

Even with the continuous improvement in electronic components in the early 20th century, there were only four patents for psychogalvanometers filed from 1928-1952:

1. C.E.W. Bellingham M.A., S. Langford Smith B.Sc. & A.H. Martin M.A. Ph.D. filed a patent in Australia in 1928 for “Some new apparatus for the psycho-galvanic reflex phenomenon.”

2. Frank Colyer filed a patent in Australia in 1932 for “A new non-polarising A.C. psychogalvanometer.”

3. John L. Raesler of New York filed a patent for an improved psychogalvanometer on January 8, 1941.

4. D.W. Douglas filed a patent for an improved psychogalvanometer on February 20, 1952.

The very few patents show that the psychogalvanometer business was an extremely small niche market. Conversely, the newspapers and magazines of the day were filled with stories about psychogalvanometric research and lie detectors. The public wanted stories about how lie detectors were used to catch bank robbers and cheating spouses in their lies and how psychiatrists and psychologists were using psychogalvanometers in research.

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