Finding the Body--and Ambiguity--in the Circuit: Historical and Reconstructive Experiments with a Spiraled Conductor

A talk by Dr. Elizabeth Cavicchi on December 10, 2003, in the Great Hall at The Bakken Museum.

Human bodies are always part of the experiments done in science, although the body´s inclusion--and its risk--may not be explicitly apparent to the experimenter. In the nineteenth century an experimenter´s body could be both detector, and subject, in research. For Harvard medical student Charles Grafton Page in 1836, the shocks he took from one hand, through his body to the other, were a way of sensing the high tension electricity that arose in his homemade spiraled conductor. He felt shocked only when battery current stopped flowing in the spiral. Page´s experimenting went further: he put the battery´s connectors and his body across different spans of the spiral. This showed something startling: the shock´s sudden electricity extended into parts of the spiral that were beyond where the battery´s direct current went. The spiral filled with an electricity that could feel painful; Page viewed this as a prospective medical treatment. 

Reproducing his novel historical effect takes a different form under today´s lab practices. The oscilloscope substitutes for the body as a detector; flashlight batteries replace the acid cells. High voltages arise within the windings of the spiral I wound by hand. However I did not observe some voltage increases that Page reported as strong shocks. This raised the question about whether the body might be operative in affecting the circuit. To check this out, I added an electrical analogue to the human body, into the circuit. It changed the shape of the voltage signals. The circuit still did not behave as Page had described, provoking me to continue investigating it in yet other ways. 

Page´s original experiment was an exploration of the spiral; my reconstruction also became an exploration of its confusing behaviors. In both these experiences, exploration emerged as the investigator´s means of working with, and extending understanding of, something in nature. This finding suggests ways that science learners today could benefit from doing exploratory work of their own.