The Road Not Taken
DURING THE 1790s, European science faced an identity crisis. For centuries, philosophers had been speculating about the nature of four mysterious substances that animated the world. They were light, electricity, magnetism, and caloric (heat). Most thought the four fluids were somehow related to one another, but it was electricity that was most obviously connected with life. Electricity alone breathed motion into nerves and muscles, and pulsations into the heart. Electricity boomed from the heavens, stirred winds, tossed clouds, pelted the earth with rain. Life was movement, and electricity made things move.
Electricity was “an electric and elastic spirit” by which “all sensation is excited, and the members of animal bodies move at the command of the will, namely, by the vibrations of this spirit, mutually propagated along the solid filaments of the nerves, from the outward organs of sense to the brain, and from the brain into the muscles.”1 So spoke Isaac Newton in 1713, and for the next century few disagreed.
Electricity was:
“an element that is to us more intimate than the very air that we breathe.”
Abbé Nollet, 17462
“the principle of animal functions, the instrument of will and the vehicle of sensations.”
French physicist Marcelin Ducarla-Bonifas, 17793
“that fire necessary to all bodies and which gives them life… that is both attached to known matter and yet apart from it.”
Voltaire, 17724“one of the principles of vegetation; it’s what fertilizes our fields, our vines, our orchards, and what brings fecundity to the depths of the waters.”
Jean-Paul Marat, M.D., 17825
“the Soul of the Universe” that “produces and sustains Life thro-out all Nature, as well in Animals as in Vegetables”
John Wesley, founder of the Methodist Church, 1760.6
Then came Luigi Galvani’s stunning announcement that simply touching a brass hook to an iron wire would cause a frog’s leg to contract. A modest professor of obstetrics at the Institute of Sciences of Bologna, Galvani thought this proved something about physiology: each muscle fiber must be something like an organic Leyden jar. The metallic circuit, he reasoned, released the “animal electricity” that was manufactured by the brain and stored in the muscles. The function of the nerves was to discharge that stored electricity, and the dissimilar metals, in direct contact with the muscle, somehow mimicked the natural function of the animal’s own nerves.
But Galvani’s countryman, Alessandro Volta, held an opposing, and at that time heretical opinion. The electric current, he claimed, came not from the animal, but from the dissimilar metals themselves. The convulsions, according to Volta, were due entirely to the external stimulus. Furthermore, he proclaimed, “animal electricity” did not even exist, and to try to prove it he made his momentous demonstration that the electric current could be produced by the contact of different metals alone, without the intervention of the animal.
The combatants represented two different ways of looking at the world. Galvani, trained as a physician, sought his explanations in biology; the metals, to him, were an adjunct to a living organism. Volta, the self-taught physicist, saw precisely the opposite: the frog was only an extension of the non-living metallic circuit. For Volta, the contact of one conductor with another was a sufficient cause, even for the electricity within the animal: muscles and nerves were nothing more than moist conductors, just another kind of an electric battery.
Their dispute was a clash not just between scientists, not just between theories, but between centuries, between mechanism and spirit, an existential struggle that was ripping the fabric of western civilization in the late 1790s. Hand weavers were shortly to rise in revolt against mechanical looms, and they were destined to lose. The material, in science as in life, was displacing and obscuring the vital.
Volta, of course, won the day. His invention of the electric battery gave an enormous boost to the industrial revolution, and his insistence that electricity had nothing to do with life also helped steer its direction. This mistake made it possible for society to harness electricity on an industrial scale—to wire the world, even as Nollet had envisioned—without worrying about the effects such an enterprise might have on biology. It permitted people to begin to disregard the accumulated knowledge gained by eighteenth century electricians.
Eventually, one learns if one reads the textbooks, Italian physicists Leopoldo Nobili and Carlo Matteucci, and then a German physiologist named Emil du Bois-Reymond, came along and proved that electricity did after all have something to do with life, and that nerves and muscles were not just moist conductors. But the mechanistic dogma was already entrenched, resisting all attempts to properly restore the marriage between life and electricity. Vitalism was permanently relegated to religion, to the realm of the insubstantial, divorced forever from the domain of serious investigative science. The life force, if it existed, could not be subjected to experiment, and it certainly could not be the same stuff that turned electric motors, lit light bulbs, and traveled thousands of miles on copper wires. Yes, electricity had finally been discovered in nerves and muscles, but its action was only a by-product of the journeys of sodium and potassium ions across membranes and the flight of neurotransmitters across synapses. Chemistry, that was the thing, the fertile, seemingly endless scientific soil that nurtured all biology, all physiology. Long-range forces were banished from life.
The other, even more significant change that occurred after 1800 is that gradually people even forgot to wonder what the nature of electricity was. They began to build a permanent electrical edifice, whose tentacles snaked everywhere, without noticing, or thinking about, its consequences. Or, rather, they recorded its consequences in minute detail without ever making the connection to what they were building.
TheINVISIBLE RAINBOW A History of Electricity and Life
by Arthur Firstenberg
