Electricity and Vital Force: Discussing the Nature of Science Through a Historical Narrative

Abstract

Seeking a historical-philosophical approach to science teaching, narrative texts have been used as pedagogical tools to improve the learning experience of students. A review of the literature of different types of narrative texts and their different rates of effectiveness in science education is presented. This study was developed using the so-called Historical Narrative as a tool to introduce science content from a historical-philosophical approach, aiming to discuss science as a human construction. This project was carried out in a 9th grade Physics class in K-12 school, in Rio de Janeiro, Brazil. The steps involved in constructing a Historical Narrative based on the controversy over animal electrical fluid between Luigi Galvani and Alessandro Volta is reported herein. Finally, qualitative research results of the activities inspired by this Historical Narrative are presented with the purpose of answering the research question: to what extent do Historical Narratives support and enhance discussions about the Nature of Science (NOS), through teaching the scientific content in a historical-philosophical approach with 9th grade students? The results indicate that Historical Narrative, based on historical episodes, is a good “door opener” to teach scientific content in a historical-philosophical approach, introducing discussions about the Nature of Science without neglecting the scientific content or simplifying the discussions about the NOS.

Appendix: Narrative “Electricity and Vital Force: The Controversy Between Galvani and Volta”

Mary anxiously walked in circles around her chamber. She seemed to be thinking deeply about something, but she knew it was pointless, hoping to occupy her mind so that the time would pass faster. She was very anxious as her father had purchased two tickets for crowded presentation that had been touring Europe and had come to her city, London.

This was not typical artistic performance you might see in London at the time. Mary was attending an outstanding scientific demonstration led by Aldini Galvani. He sought to publicize new scientific knowledge from an area that had been attracting the attention of all of Europe: electricity.

When the time came, William, Mary’s father, said goodbye to his servants, leaving his chambers and walking towards her daughter’s bedroom. Taken by surprise, he found her, already groomed, in the lobby of his home. Father and daughter, both showing a disguised nervousness, headed towards the carriage that would take the family to the amphitheater.

Entering the amphitheater where the presentation would take place, Mary finds their seats a little further back from the central podium, and tells her father that she would like to sit closer to the speaker. When looking at the audience, she noticed numerous well-known figures of her city. From successful business people to famous politicians, all settled in their seats, a waiting for what would happen tonight.

Faced with a not requested silence from the audience, Aldini walks down the stairs, causing the audience to sigh in unison. Beside him, helpers bring materials wrapped in fabric and inside large boxes. With the materials displayed on the large table, Aldini directs himself to the audience:

“Ladies and gentlemen, welcome. Today I bring you what will be unforgettable experiences that may cause nightmares. Many scholars and intellectuals will try to disprove what will be reproduced here tonight. However, I will show you the latest scientific achievements made by me and the famous scientist, Luigi Galvani, my uncle. Without further delay, we will begin with the least startling and then we will demonstrate the most impressive experiences while our audience still has breath”.

His helpers put some instruments on the table, as well as a tray that contains something that seems to Mary to be tiny paws of some animal. Turning to the audience, Aldini brings out some wire made from different materials:

“As you can see, I have in front of me bodies of dissected frogs, therefore, completely dead, unless someone doubts this!”—he continues—“Then I select two different wires among those placed here, composed of different metals, and unite both. For those of you who know anatomy, I will position each free end of the wire on one part of the leg nerve of the frog. I urge the full attention of all to what will happen”.

Without even realizing that she was standing, Mary witnesses what her eyes refuse to believe. When connecting the wires as described, the separated and dissected frog legs contracted, a recoiling movement resembling its natural movement while alive. Aldini did not hold back before the general astonishment of the audience, continuing his presentation by positioning the wires on other parts of the frog, causing nerves to contract as much on the frogs, as in the audience, who watched not believing what they saw.

“As my uncle initially proposed 11 years ago, in 1791, these results prove that there is something in the body of these frogs that is released at the contact of those metals. The contractions do not lie that frogs experience some electrical phenomenon. I dare to agree with my uncle that their bodies contain some animal electricity, whose release we are enabling through contact with such metals. But there are those who try to sabotage us, questioning the limitation of these experiments using the bodies of simple frogs. So, for the second part of this presentation, I bring you new subjects”.

Then, his assistants exhibit trays with new body parts from dissected dogs, and heads of oxen, while Aldini keeps repeating the same procedures. These again result in terrifying contractions, while William watches his daughter, only 18, scared and standing in front of her seat. However, neither suspected what the third part of the presentation would bring. A stretcher is brought to the front of the table, revealing a naked human body.

“I present to you Forster, a famous murderer, guilty and executed for killing his wife and daughter. His only contribution in life, or better, on Earth, will be to help us prove the existence of this fluid in humans. For more intense effects we will use a sequence of different metals to facilitate the release of the fluid”.

A small tower, composed of alternate stacks of two metals was placed standing beside the corpse. Aldini connects wires to the extremities of the tower and starts the demonstrations. In the beginning, the criminal’s jaw began to quiver, the adjoining muscles contorted horribly and one eye actually opened. Applying the wires to different body parts, a hand rose and clenched, and legs and thighs were set in motion.

Mary remembered little of the rest, at the moment she and her father walked back home, they agreed that they needed a moment to reflect.

“You are very quiet, Mary, what is disturbing you?

What does not bother me would be the question. To what extent these scientists are coming! Is it not dangerous to try to control the essence of our body, playing with life itself?

Daughter, what guarantees that what they call animal electricity is coming from the animal itself? Note that in all experiments Aldini uses not only metals but different metals. Alessandro Volta himself had already noticed it. Volta argues that electricity comes from the encounter between these metals and not the animal. This one would only serve as a conductor of electricity, not a creator or store. It was precisely based on this idea that he created the pile that Aldini used on the corpse. This pile should prove once and for all that the electric fluid does not come from animals, but the metals, however, many still disagree about its effect. Perhaps Volta should make presentations like Aldini to persuade the audience”.

The explanations of the Mary’s father calmed her of the “horrors” that she witnessed, but there were still questions regarding what they call electricity. Mary was puzzled that this same name was associated with both the pile as with other phenomena such as frictional electrification. Amid so many questions, Mary reflected on a quite intriguing idea:

“Dad, tell me something. We saw the movements of those animals when connected to that pile in their muscles and nerves. They looked so alive! What would happen if they increased the pile say by ten times the size? Maybe I’m fantasizing, but would it be possible to make those bodies come back to life?”

After a few seconds of silence, her father said,

“Daughter, this is a question for which I cannot imagine an answer, but one thing is certain: this would be an amazing horror story!”