December 1937 Radio-Craft
[Table of Contents]
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Craft,
published 1929 - 1953. All copyrights are hereby acknowledged.
with the article in this month's issue of Radio-Craft
magazine (December 1937), the
reference to a 200th anniversary is understated by 78 years
for 2015. Luigi Galvani was sort of the Benjamin Franklin of
biology in that just as Franklin demonstrated that lightning
was a form of electricity, Galvani showed that signals sent
from the brains to the appendages of animals were electrical
in nature. In my high school days in the 1970s, we duplicated
his experiment by making deceased frogs' legs twitch when motivated
by a D cell. Today, such an exercise would likely be met with
demonstrations by animal rights people
(whose lives, BTW, have probably in some
way been improved as a result of previous such experiments).
But, I digress. Mr. Galvani's name is now paid attribution
through the many words based on it, such as galvanization, galvanometer
(mechanical meter movement), galvanic
corrosion (eroding of dissimilar metals),
Luigi Galvani - 200th Anniversary
"Father of Electricity" Luigi Galvani opened for posterity
a door that has swung ever wider to reveal the world, of wonders
now termed, in his honor, "galvanic electricity."
Italy pays a tribute to the man who inspired
Volta, Ampere and other scientist-pioneers by issuing a postage
stamp in Galvani's honor. His life spanned the period between
the years 1737 and 1798; he died in Bologna, Italy, where he
was born. (Photo - R.P.S., Paris.)
Last September 9th, we celebrated the 200th anniversary of
Luigi Galvani who has often been called the "Father of Electricity."
We will seize this opportunity to recall the life of the great
Italian scientist and research worker who gave his name to many
a word used now in radio and physics, such as galvanism, galvanometer,
galvano plastics, galvano surgery, galvanography, galvanic cell
and others which have often resounded to the ears of all those
interested in scientific questions.
Luigi Galvani was born in 1737 in Bologna. He studied medicine
and became a professor in 1762. His first researches were directed
towards natural history and all that concerns life's phenomena.
His studies relative to the brain constitution of birds,
obtained such a great success that he decided from that time
to devote himself to the study of bird physiology. However he
soon realized that the subject he had chosen offered too wide
a field of experiment for which he could not find sufficient
time and he therefore limited his studies to the close examination
of the auditory system of birds.
Under this emblem of Galvani's frog's legs
experiments were held, a few years ago, sessions of the first
Congress treating of Radio Biology. (From
Frog's Legs Mark Radio-Electrical Epoch!
It was only by chance, so it seems, that he was brought,
on November 6, 1780, to discover what was later named "Galvanism",
which consists in producing electricity by means of a contact
established between 2 substances of different nature. This experiment
of his, which has become universally known as "Galvani's frog's
legs experiment," marks an epoch in electrical (and radio) history.
Little indeed was known 200 years ago about electricity.
All that had been transmitted to us through our ancestors was
that a piece of well-polished yellow amber was known to possess
the property of momentarily attracting certain light substances.
Researches were actively pursued during the 17th century but
they gave very poor results, until Benjamin Franklin discovered
the identity of lightning and electricity and constructed the
first "lightning rod." However, it was not until Galvani made
his experiments that the difference between (1) static electricity
produced by the mere frictional contact of 2 different substances,
and (2) dynamic electricity which can be obtained chemically
and is found to pervade matter and the earth, was demonstrated.
Later on, Volta came and devised the cell, and then almost immediately
its derivative, the battery, which made available practicable
amounts of electricity.
It was sheer chance, we repeat, which brought Galvani to his
discovery. One day, as a Professor of Anatomy, he was observing
the contractions of a frog's legs which became animated with
a sort of spasm each time a flash came out of an electric conductor
The contractions were, without doubt, but simple reactions.
However, Galvani saw in them but the confirmation of a theory
which was dear to him, mainly that they were due to the electricity
(later to be called "animal electricity") contained in the animal
body. From that time. he devoted himself, heart and soul, to
these particular experiments.
He continued to use frogs' legs and one day. he hung some
of them on the railing of his balcony. He noticed that violent
reactions were produced every time he brought the frog's legs
near the iron railings. The contractions were even more noticeable
when he would bind the nerves or spine of the little animal
to its muscles by means of a metallic wire. Galvani concluded
from that, that frogs' legs could be considered as matter charged
with electricity, and that the nerves and muscles of which they
were constituted could be "unloaded" (discharged) like a condenser
by means of the metallic wire. However, he had noticed that
the contractions of the frog's legs were even more pronounced
when the wire employed was made out of 2 different metals.
Alessandro Volta, Professor of Physics in Pavie (Italy),
inspired himself with those experiments and found that the source
of electricity was to be identified with the metal and not,
like Galvani had believed, with the animal body. Following this
he made important discoveries, and found among other things
that 2 metallic substances of different nature when put into
contact, with one another, produce opposite electricity. Yet
by denying the presence of electricity in animal bodies. he
made a mistake as was to be demonstrated later on.
It would take us too long to follow, step by step, these
wonderful experiments. However before concluding, let us add
that in later years, Oerstedt, Arago and Ampere discovered the
identity of magnetic and electric currents; they succeeded in
obtaining electric currents from magnetic ones, and vice versa.
As a science, electricity may be said to exist only from that
date. Since then it has not ceased to progress with giant strides
and one may verily say that it now governs our whole existence.
Galvani's life went on afterwards in quietness and peace
and there remains nothing else worth mentioning except the fact
that during the Revolution, having refused to take the oath
of fidelity towards the new constitution, which all officials
were obliged to do, he was forced for a time to retire from
his post which, however, he was not long to take up again. He
died in 1798 in Bologna, Italy, which raised a monument
to his memory in 1879.
Galvani's electroplating experiment.
Posted September 30, 2015