Animal electricity from Bologna to Boston

Abstract
Animal electricity from Bologna to Boston
Eli S. Goldensohn*
Montefiore Medical Center, Albert Einstein School of Medicine, 111 East 210th Street, Bronx, NY 10467–2490, USA
Accepted for publication: 3 October 1997
This is an appreciation of 3 scientists who made historic contributions toward understanding bio-electrical activity. The discoveries of
Galvani and Volta, who were contemporaries two hundred years ago, continue as basic supports in advancing the strength and health of all
mankind. They, nevertheless, had political and scientific disagreements that still linger. The third scientist was our contemporary, Alexander
Forbes who, throughtout most of the 20th century, continued to increase our understanding of electrical activity in the nervous
system. © 1998 Elsevier Science Ireland Ltd.
Keywords: Amplifiers; EEG; Electricity; History
1. Introduction
The early days of electroencephalography (EEG) in the
USA can be traced to the department of physiology at Harvard
under the neurophysiologist Alexander Forbes. Forbes
made many significant advances in electrophysiology and
neurophysiology. He used the epic-making discoveries of
two earlier scientists, Galvani and Volta, as the basis for his
investigations. Luigi Galvani discovered intrinsic electrical
transmission in the peripheral and central nervous system.
Alexandro Volta invented a method of continuously generating
and storing electricity that changed the lives of everyone
in innumerable ways, and particularly for those of us in
electrophysiology. Volta and Galvani were contemporaries
and were also adversaries.
2. The great Galvani versus Volta debate
Luigi Galvani was born in 1737 in Bologna. Long before
he was born, frictional electricity was produced by rubbing
glass, amber or rubber by hand, to produce momentary
shocks. By the time of his birth, frictional electric machines
had been invented which were used by the curious for amu-
* Tel.: +1 718 9205603; fax: +1 718 8810838.
Electroencephalography and clinical Neurophysiology 106 (1998) 94–100
sement and speculation (Nollet, 1746). Some serious but
inconclusive stimulation studies were made with advanced
frictional models by Aldini (Hintzsche, 1966; Fig. 1). Other
shock methods were also used later as putative treatment for
illnesses and in attempts to raise the dead (Aldini, 1804; Fig.
2). When Galvani was 8 years old, in 1746, a physicist
named Van Musschenbrock, in Leyden, The Netherlands,
developed a method for storing frictionally produced electricity
in jars until needed (Dorsman and Grommelim,
1957). In his research, Galvani used the friction-generated
charges held in the Leyden glass jars (capacitors) to stimulate
frogs at will. After 11 years of meticulously planned and
personally illustrated experiments on intrinsic electricity
(Fig. 3), he presented his work in an historic treatise. It
was published locally in Latin in 1791 by the Institute of
Academic Commentary (Fig. 4; Galvani, 1791). It clearly
showed that electrical stimulation of a peripheral nerve
would cause an impulse to travel to and throughout the
spinal cord, and in turn exit and arrive distally to cause
the leg muscles of an insulated frog to contract. Nevertheless,
for the next half century his profound discovery, which
he called ‘animal electricity’, was not generally accepted,
although it had been independently con-firmed (Aldini,
1794; Von Humboldt, 1797; Volta, 1800; Fig. 5).
This 50 year scientific hiatus occurred mainly because of
the influence of Galvani’s renowned countryman and critic,
0013-4694/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved
PII S0013-4694(97)00110-7 EEG 28

E.S. Goldensohn / Electroencephalography and clinical Neurophysiology 106 (1998) 94–100
Fig. 1. Left: Marcantonio Caldani (1725–1813), Professor of Medicine at Bologna, from the engraving by Gaetano Bozia after the portrait by Schiavoni
(courtesy of the Wellcome Institute of History of Medicine, London). Right: the electrostatic machine made by Dolland in London and used by Caldani and
Fontana in stimulating experiments to study irritability of tissues (Instituto delle Scienze, Bologna).
Alessandro Giuseppe Anatonio Anastasio Volta (Fig. 6).
Volta was informally well-educated with a particular
interest in physics. As a young man he did creditable
work in that area and was made a professor at the University
of Pavia. His historic invention, the voltaic pile (Fig. 6), was
a series of plates of dissimilar metals (copper and zinc)
Fig. 2. Left: Giovanni Aldini (1762–1834), nephew of Galvani. Right: Aldini’s experiments with electric shock in various positions connecting to voltaic
piles for stimulation. Below: two recently dead patients connected (Aldini, 1804).
95

96 E.S. Goldensohn / Electroencephalography and clinical Neurophysiology 106 (1998) 94–100
Fig. 3. Galvani’s laboratory in 1792. Sketch of 3 frog nerve–muscle preparations in insulated flasks, a Leyden jar, two hand-held metal wands to transfer
charges, and metal wire suspended from the ceiling to collect and carry the charge to the frog (courtesy of the National Library of Medicine, Bethesda, MD,
USA).
separated by moist separators that generated continuous
electrical ‘tension’ (the electric storage battery) which revolutionized
the use of energy in the world forever. Although
Volta was originally friendly with Galvani and accepted his
findings, he soon turned against them and tenaciously and
incorrectly ascribed all of Galvani’s results to ‘metallic
electricity’ from the inadvertent use of two dissimilar metals
that had directly stimulated the frogs’ muscles (Volta,
1800).
Both Galvani and Volta lived in northern Italy, a region
that the French army had begun to wrest from Austria in
1792. This was just a year after the publication of Galvani’s
‘Commentary’. Napoleon completed the conquest of the
area early in 1797, and Volta, who was politically sophisticated,
supported the conquest. After Napoleon declared
himself President of the Lombardy region in northern
Italy, he bestowed the title of Count of the Royal Kingdom
of Lombardy upon Volta for his scientific achievements and
his political support. Volta became an internationally
honored figure. Up to the time of his death at the age of
82 years, he remained strongly against the proof of intrinsic
electricity. In contrast to Volta, Galvani was not honored
during his lifetime, and for many years thereafter his conclusions
did not gain general acceptance. Because he
refused to take an oath of allegiance to Napoleon’s new
state, he lost his positions at the University of Bologna
and the Institute of Science. When he died in December,
1978 he was neither honored nor generally believed. Galvani’s
discovery was not accepted for years, mainly because
Volta outlived him, and continued to publicly deny the
validity of Galvani’s work for 3 decades.
3. Electrophysiology as a field
Finally, in the mid-19th century, general acceptance of
intrinsic electrical activity in nerve and muscle was sparked
by the German physiologist Emil Du Bois-Reymond in his
two volume book Untersuchungen uber Thierische Elektricitat
[Investigations on Animal Electricity (Du Bois-Reymond,
1848; Du Bois-Reymond, 1849); Fig. 7]. In 1937,
Fig. 4. Luigi Galvani (1837–1882) portrayed in his middle age.

E.S. Goldensohn / Electroencephalography and clinical Neurophysiology 106 (1998) 94–100
Fig. 5. Frederick Alexander von Humboldt (1769–1859) confirmed and extended Galvani’ experiments and supported Galvani in opposing Volta’s contention
that current generated by dissimilar metals were responsible for the effects in animal tissue. On the left, the frog muscle contracts (dotted lines) after the
action potential passes down the crural nerve below the two contacts. On the right is a drawing of Humboldt as a young man. His experiments were published
when he was still in his twenties.
200 years after Galvani’s birth, the Institute of Science celebrated
his life accomplishments and republished his treatise.
In spite of the politics of scientific jealousy and nationalism,
his place in history was finally secured.
Georg Ohm discovered the laws governing flowing electricity
in 1827. In 1858 William Thompson refined the galvanometer,
and the field of electrophysiology became the
basis of the physiology of the nervous system as proposed
by Carlo Matteucci and Emil Du Bois-Reymond in the mid-
1800s. Du Bois-Reymond also made non-polarizable electrodes.
This period also gave rise to the concept of ‘action
current’ (Hermann, 1834–1919), to the accurate measurement
of the velocity of nerve conduction (Von Helmholtz
(1812–1894) and a membrane theory of nerve tissue (Bernstein,
1839–1917).
In 1929, Hans Berger, credited with naming and discovering
the human electroencephalogram, published the first
report on the characteristics of the alpha rhythm and alpha
blocking. This gained increasing acceptance after its confirmation
by Adrian and Matthews (1934) in 1934, and a few
months later by Jasper and Carmichael (1935).
4. Alexander Forbes, the father of American EEG
A little more than a century after Galvani’s discoveries,
Fig. 6. Left: Alessandro Volta (1745–1827) from the portrait by Roberto Focasi. Volta was an admirer of and honored by Napoleon, one of whose gestures he
seems to have caught. Right: his own sketches of voltaic piles.
97

98 E.S. Goldensohn / Electroencephalography and clinical Neurophysiology 106 (1998) 94–100
Fig. 7. Emil Du Bois-Reymond (1818–1896). His experiments and innovative electrical apparatus reopened the field of electrophysiology in the middle of the
19th century. The preparation on the left shows his apparatus which demonstrated change in flow of current when nerve is stimulated. (Portrait courtesy of the
National Library of Medicine.)
Alexander Forbes began his contributions to electrophysiology
and EEG in Boston. From the age of 19 years in 1901,
Forbes was scientifically productive until he published his
last two papers on the physiology of color vision at the age
of 80 years (Fig. 8). Many who worked in the field when the
American and Western EEG societies were founded (1936–
1946) already regarded Alexander Forbes as the premier
American electrophysiologist. Much of the following material
is drawn from Wallace Fenn’s appreciation in the Biographical
Memoirs National Academy of Sciences (Fenn,
1969) and from Sir John Eccles’ evaluation of Forbes’ contributions
(Eccles, 1970).
Forbes was born into an illustrious Massachusetts family
in 1882. Both sides were to influence him philosophically,
politically and scientifically. His grandfather, John Forbes,
helped organize Negro regiments in Massachusetts during
the Civil War and made a fortune in the budding railroad
industry. His father, Julian Forbes, was a Civil War hero
who latched on to another nascent technology and became
president of the Bell Telephone company. His mother, Edith
Emerson Forbes, was the daughter of the great philosopher
and humanist Ralph Waldo Emerson, and from her he
absorbed a high regard for self-reliance and a liberal religious
reverence for nature. At Harvard College, Forbes
decided to be a biological investigator, and completed several
scientific papers while attending the medical school
there. He then spent 2 years in England in the laboratory
of the great neurophysioloist Charles Sherrington (the future
Sir Charles) on central nervous system integration, including
reflex excitation and reciprocal inhibition. When he
returned to Harvard, he added electrical recording to the
study of spinal reflexes for the first time. He made subsequent
trips to England, and in 1921 visited E.D. Adrian
(later Lord Adrian; Fig. 9) who, incidentally, taught him
Fig. 8. Alexander Forbes (1882–1965).

E.S. Goldensohn / Electroencephalography and clinical Neurophysiology 106 (1998) 94–100
Fig. 9. Alexander Forbes (left) with Sir Charles Sherrington (middle) and E.D. Adrian in England in 1938 (photo by Mrs. W.A. Locke). From Fenn, 1969.
to fly. From then on, until he was 80 years old, he piloted his
plane to scientific meetings.
In World War I, Forbes became an expert in electronics
and did research in radio communication. In World War II,
he was a captain in the Navy where he used his mastery of
electronics and geography to solve navigation and tactical
problems. He flew his own plane while making photographic
maps of shore lines. Another of his assignments
was to use EEG to test the suitability of candidates to
train as airplane pilots. Many candidates were probably
refused because delta slowing in the electroencephalogram
in response to hyperventilation was considered ‘abnormal’
at the time.
One of Forbes’ greatest accomplishments was to devise
and introduce the first electronic vacuum-tube amplifier for
research in neurophysiology (Forbes and Thatcher, 1920;
Fig. 10). It greatly increased sensitivity and frequency
response over the galvanometer by some 50-fold and
opened a new era of research in electrophysiology. The
vacuum-tube amplifier remained dominant in electrophysio-
logical research for the next 30 years until it was superseded
by the transistor. Not long after Forbes introduced tube
amplification, a young psychiatrist in training, named
Donald McPherson, who was moonlighting in a Harvard
affiliated psychiatric hospital, came to Forbes’ laboratory
with a research plan. McPherson explained that the wellto-do
aunt of a psychotic youth he was treating had asked if
he had any idea of the cause of the youth’s mental illness.
McPherson told her that the brain contains many cells which
carry and distribute electrical messages in much the same
manner as wires that distribute messages among telephones,
and that in the patient’s head the ‘wires might be crossed’.
She offered to underwrite his research into this theory, and
thus began the search for schizophrenia in aberrant cortical
connectivity. Forbes allowed McPherson to use his amplifier
and camera to look for spontaneous activity in the
exposed cortex of cats. After some trials, McPherson saw
some fluctuations on the film. He brought it to Forbes, who,
being busy with other things, suggested that the fluctuations
might be artifactual from construction next door. Forbes put
Fig. 10. First use of valve amplification in recording action potentials of nerve. Left: a frog sciatic nerve, N, with stimulating electrodes, S, and recording
electrodes, L, applied to nerve in moist chamber. The nerve is shown crushed between the two electrodes in order to give a monophasic recording. The
recording circuit is shown as passing through a valve (vacuum-tube amplifier) to a string galvanometer, G. Right: submaximal and maximal action potentials
are shown without amplification in C and E, with amplification in B and D (Forbes and Thatcher, 1920).
99

100 E.S. Goldensohn / Electroencephalography and clinical Neurophysiology 106 (1998) 94–100
the film in the top of his old-fashioned roll-down desk where
it sat undisturbed and forgotten. Years later, Hallowell
Davis accidentally discovered the film. Forbes reportedly
presented the story and film at a meeting and published
the material. Davis credits both Forbes and McPherson in
his obituary of Forbes (Davis, 1965), as does Fenn (1969).
The original paper is not listed in Index Medicus nor the
Biographical Memoirs National Academy of Sciences, each
of which should have listed all of Forbes’ papers, so it
appears officially absent from written scientific history.
However, unbeknown to Forbes, McPherson or Davis, a
Russian researcher had already published the first photographic
record of the electrocencephalogram in 1912 (Pravdich-Neminsky,
1912).
Of equal importance to the new amplifiers that Forbes
devised was the neurophysiological research he accomplished
using his amplifiers. He confirmed the ‘all-or-none
law’ of nerve impulse conduction. Alone, and in collaboration
with neurophysiologists in England and America, he
completed scores of other important investigations in the
central nervous system, including evoked potentials during
anesthesia. Using microelectrode recording on single brain
cells with Renshaw and Hallowell Davis in 1940, they lead
the way toward establishing the synaptic origin of EEG
waves (Renshaw et al., 1940).
Harvard maintained eminence in EEG with the work in
humans by Hallowell and Pauline Davis, Frederic and Erna
Gibbs, William Lennox. Herbert Jasper led the movement
out of Brown University in Rhode Island, and Lee Travis at
the University of Iowa founded the EEG group, which later
included Jasper, Donald Lindsley, John Knott and Charles
Henry. Donald Lindsley transferred his zeal for electrophysiology
to the west coast where he published on EEG for
many years, out of the Psychiatry Department of University
of California, Los Angeles.
I recall Forbes from his later years, listening attentively
with his hearing aid from the front row of the Eastern EEG
Society Ski Meetings in the Laurentian mountains, offering
gentle but critical analysis of the work and then racing all
afternoon on his short barrel, stave-shaped skis. Toward the
end of his life he left us an important message about science,
‘Science can perform its noblest service, not in laying the
foundation for labor saving inventions, not even in improving
medical services of the sick, but in giving us a clearer
understanding of man’s place in the order of nature and the
origins of his patterns of behavior that ultimately guide us to
a more harmonious way of living with each other.’
References
Adrian, E.D. and Matthews, B.H.C. The Berger rhythm: potential changes
in the occipital lobes in man. Brain, 1934, 57: 355–385.
Aldini, G. De Animali Electricitae Dissertationes. Duae, Bologna, 1794.
Aldini, G. Essai Theorique et Experimental sur le Galvanisme, 2 Vols.
Fournier, Paris, 1804.
Davis, H. Alexander Forbes, 1822–1965. J. Neurophysiol., 1965, 28: 986–
988.
Dorsman, D. and Grommelim, C.A. Invention of the Leyden jar. Janus,
1957, 46: 275–280.
Du Bois-Reymond, E. Untersuchungen uber Thierische Electricitat, Vol. I.
Reimer, Berlin, 1848.
Du Bois-Reymond, E. Untersuchungen uber Thierische Electricitat, Vol.
II, Reimer, Berlin, 1849.
Eccles, J.C. Alexander Forbes and his achievements in electrophysiology.
Perspect. Biol. Med., 1970, 13: 388–404.
Fenn, W.O. Alexander Forbes. Biogr. Mem. Natl. Acad. Sci., 1969, 40:
113–141.
Forbes, A. and Thatcher, C. Amplification of action currents with the
electron tube in recording with the string galvanometer. Am. J.
Physiol., 1920, 52: 409–471.
Galvani, L. De viribus electricitatis in muto musculare commentarius
1791, 7: 363–418. De Bononiensi Scientiarum et Artrium Instituto
atque Academia Commentarii, 1791, 7: 363–418.
Hintzsche, E. (Ed.). Albrect Von Heller–Marcantonio Caldani. Huber,
Berne, 1966.
Jasper, H.H. and Carmichael, L. Electrical potentials from the human
brain. Science, 1935, 81: 51–53.
Nollet, J.A. Essai sur l’Electricit :é du Corps Humain. Guerin, Paris, 1746.
Pravdich-Neminsky, V.V. Eim Versuch der Registrierung der elektrischen
Gehirnerscheinungen. Zbl. Physiol., 1912, 27: 951–960.
Renshaw, B., Forbes, A. and Morison, B.R. Activity of isocortex and
hippocampus: electrical studies with microelectrodes. J.
Neurophysiol., 1940, 3: 74–105.
Volta, A.G.A. Letter to Sir Joseph Banks, 20 March 1800, on electricity
excited by the mere contact of conducting substances of different kinds.
Phil. Trans. R. Soc., 1800, 90: 403.
Von Humboldt, F.A. Versuche uber de gereizte Muskel and Nervenfaser.
Decker, Posen und Rottman, Berlin, 1797.