- How did Galvani make a dead frog jump?
And how did that lead to the battery?
And hey, didn't a guy named Volta invent the battery?
Well, I'll tell you.
And along the way,
I'll talk about professional misconduct,
a surprising accident,
the inspiration for Frankenstein
and the building blocks of life.
Ready? Let's go.
♪ Electricity, electricity ♪
- Sometime in 1790 or 1791,
an Italian anatomy professor named Luigi Galvani
was playing with electricity machines
and hoping to find something interesting to publish.
See, Galvani was a member of the Academy of Sciences
at the Institute of Bologna
and he needed to submit a research paper every year.
For the previous four years,
he had published research on the hearing of various animals.
However, that year his work was stolen by a rival.
So, he needed a new research subject and quickly.
Therefore he turned to the newish subject of electricity
and got several assistants to help him.
He had static electricity machines
that you could spin to produce large static charges
and jars called leyden jars,
that could store the charge and give it a terrifying jolt,
when you connected them in a circuit.
One day, unrelated to his electricity experiments,
he happened to put a dissected headless frog on the table,
while his assistants were running
these electrical experiments.
He never said why he was cutting up frogs
in the first place.
A popular myth,
is that he was making frog soup for his sick wife.
However, it seems much more likely
that he was dissecting the frog for anatomy lecture.
He was an anatomy professor after all.
Anyway, there was a dissected frog on the table.
Here is how Galvani described what happened next.
Quote, "I had dissected and prepared a frog,
and I had put it on the table
where there was an electric machine.
As soon as one of my aides, by accident,
touched the internal nerves of the frog with a scalpel,
at once, he saw all the muscles go into violent convulsion."
Galvani was deeply surprised
to see the headless frog jumping
and did a series of bizarre and macabre experiments,
like frogs in a jar, and frogs in a circle,
to determine what would make the frogs dance.
Galvani or honestly, his assistant,
discovered two things with this experiment.
First, they found that frog legs
are an extremely sensitive machine for sensing electricity.
Superior by a factor of 5000
to anything non-biological available at the time.
Secondly, and more importantly,
Galvani started the study
of how electricity works in living systems.
He found that muscles contract with electricity
and nerves send messages with electricity.
In truth, electricity is the building block
of living systems.
We think with electricity,
we hear and see and smell with electricity.
Our hearts pump with electricity
and our muscles move with electricity.
This is not just true for frogs.
All animals' biological systems are electrically based.
Now, it took a further 150 years
to truly understand the complex beauty
of the biological system,
but Galvani started us on that path.
Galvani then decided to move his frog experiments outside,
to see if thunderclouds could make the frog jump
as well as static electricity would.
This was 38 years after Benjamin Franklin
flew his kite in the storm.
So he's not surprised at all,
to find the frog jump theatrically in thunderstorms.
However, something else happened that was truly unexpected.
Sometimes the frog would jump on clear days
with no static electricity,
or atmospheric electricity involved at all.
What was going on?
At first, Galvani wondered if the frog stored electricity
from past atmospheric storms.
However, soon he realized
it had nothing to do with the weather,
it had everything to do with his garden.
See, Galvani had iron railings surrounding the garden
that he hooked his frogs on.
He also used copper hooks to transport the frogs.
It was this combination, the iron and the copper,
the cause of the frog to convulse.
When he took the frog inside,
he could make a frog dance
with just a piece of copper and iron. Crazy, huh?
This is a major find.
Putting copper and iron into a frog,
produces electricity with no rubbing globes
or thunderstorms in sight.
Galvani decided that the frog moved
because it had been alive in the past.
He thought he was reanimating the frog,
a la Frankenstein,
whose author was inspired by Galvani's research, by the way.
Galvani published his work in 1791
and it was an international sensation,
especially among anatomists.
Suddenly, there was a way of studying how muscles move
and how nerves communicate.
He had connected electricity to what makes things alive.
He had made the spark of life literal.
Gavani didn't know it,
but he had also invented the first battery.
The acid in the frog leg reacted with the copper
to add electrons and reacted with the iron
to remove electrons.
The electrons then flowed through the frog leg,
from the copper to the iron, making the frog leg jump.
In terms of physics,
it was a completely useless battery
as it discharged inside itself.
This is why most people don't consider
his invention a battery.
However, there was a man named Alessandra Volta,
who was supposed to be Italy's leading expert
on electricity.
He became obsessed with jealousy over Galvani's fame,
which led him to inventing the first non-biological battery.
This was the battery that changed the world
and that is why batteries are measured in volts,
in his honor.
And that crazy story,
is next time on the Secret History of Electricity.
♪ Electricity, electricity ♪
- Thanks for watching my video,
please remember to give it a nice thumbs up.
Also make sure to check out that video
about how Volta invented the battery, it's a good story.
Finally, if you wanna know how a modern battery works,
watch my video, How a Battery Works,
a simple explanation for adults.
And make sure to join my YouTube page
called Kathy Loves Physics,
my Facebook page called Kathy Loves Physics,
or my website called www.KathyLovesPhysics.
Okay, have a good day.
(upbeat music)
(woman indistinctly speaking)