A long-exposure photograph shows lightning bolts illuminating the night sky north of Barstow, California, in 2015.Gene Blevins / Reuters

It must have seemed like black magic when humans first harnessed the power of electricity. How else could you explain the ability to illuminate the night without flame or fire?

In this superhuman triumph over Mother Nature, in the late 19th century, a cultural obsession was made. And because electricity was the future, anything electric became the ultimate symbol of modernity. That included an array of electric wearables that were sold as cure-alls for any number of ailments.

The electric belt was popular—but so were rings, corsets, hairbrushes, towels, garters, toothbrushes, and other inventions. A single device would often promise to soothe or eliminate a wide variety of afflictions: bronchitis, shortness of breath, liver complaints, rheumatism, lumbago, sciatica, gout, kidney complaints, paralysis, indigestion, constipation, asthma, weakness, “female complaints,” hysteria, general and local debility, functional disorders, bad circulation, writer’s cramp, palpitations, and so on.

Devices were marketed slightly differently for men and women, however. For men, electric wearables were often promoted as being able to enhance sexual performance, whereas “electrical corsets were available for women, less to augment their sexuality than to control it,” wrote Carolyn Marvin in her book, When Old Technologies Were New. One inventor described electric corsets thusly: “If one of these articles is pressed by a lover’s arm it at once emits a shriek like the whistle of a railway engine.”

The devices were touted as being groundbreaking, on par with the telephone and electric light. Advertisements for electric belts were splashed across newspapers and catalogs with “eye-catching graphics and rhapsodic testimonials [that] promised what the physician could not: cures,” wrote John Greenway in Pseudo-Science and Society in Nineteenth-Century America.

The Heidelberg Electric Belt, advertised in Sears, Roebuck and Company’s catalog in 1900.
(University Press of Kentucky)
An 1901 advertisement in The Pacific Commercial Advertiser (LoC)
A 1910 ad for Dr. McLaughlin’s Electric Belt, published in The Daily Arizona Silver Belt (LoC)

“As bizarre as such illustrations seem today,” Greenway wrote, “at the time they embodied metaphors of a new but legitimate field for biological research.”

So while there was no real evidence that these wearables did what they promised, they occupied a strange space between medical quackery and true scientific inquiry. Much of that science seems absurd (and outright dangerous) in retrospect. It was around this time, in France, that the naturalist Pierre Jean Claude Mauduyt de La Varenne experimented with submerging patients in electric paths, using sparks as an early kind of shock therapy.

Eventually, these early ideas about electricity fell apart. “Not only was there no neural fluid, electricity was not a fluid after all,” Greenway wrote, meaning “terms such as ‘current’ and ‘flow’ could now only be used metaphorically.”

Doctors didn’t really understand the intersection of electricity and anatomy, but they were beginning to piece together ideas that would lay the groundwork for subspecialties of contemporary medicine like electrophysiology and epileptology.

We now know that the cells of the human body, at a fundamental level, have electrical properties. But in the age of electric belts, “the therapeutic effects of the unseen world of electricity seemed equally unintelligible to scientists and quacks alike,” Greenway wrote. Pseudoscience, as it so often does, had rushed in to explain what people didn’t yet comprehend—and to capitalize on a cultural cocktail of misunderstanding and technological awe.

A century ago, treatment centers promised electromagnetic therapy and access to “metallic tractors” that could cure a variety of ailments when rubbed over the afflicted region. “Although part of the early interest in electrotherapy went the way of entertainment and quackery,” Greenway wrote, “that ‘quackery’ often becomes obvious only in retrospect.”

A 1909 advertorial for electric belts in the Los Angeles Herald (Library of Congress)

The influence of modern technology on medical thinking, too, becomes more pronounced in hindsight. The way the human brain is often compared to a computer today, scientists of the 19th century saw the body as a battery that needed charging. Consider, for example, the primary ailments that electric wearables were meant to cure, such as “lost vitality” and “lack of nerve force.”

Doctors saw these conditions, along with nervousness and anxiety generally, as distinctly American and directly linked to social stressors of the day—including “steam power, the periodical press, the telegraph, the sciences, and the mental activity of women,” according to George Beard’s 1881 book, American Nervousness: Its Causes and Consequences. (“Women, being as a rule of smaller stature than men,” Greenway explained, “were assumed to have less ‘nerve force’ than men. Naturally, they would be more prone to nervous overload as they attempted mental activity,” which was regarded as “unusual, debilitating, and, some argued, unnatural,” for women.)

Both today’s computer-brain comparisons and yesterday’s battery-body analogies are imperfect—and both are steeped in the culture and technological orientations of their respective eras.

“The word health now means a normal supply of electricity in the body, and the word disease means an insufficiency of that power,” explained one 1909 advertorial for electric belts that appeared in The Los Angeles Herald. As my colleague Julie Beck wrote, this idea was shaped largely by anxiety about technological progress.

A prominent medical theory at the time was that the human body was like an electrical machine, powered by energy distributed through the nervous system. An unfortunate byproduct of the teeming cities and their attendant problems was that people spent too much of this “nervous energy” and when it was depleted, they got sick with a condition called neurasthenia. Both [the physician S. Weir] Mitchell and George Beard, a neurologist who coined the term in 1869, saw the disease as a direct consequence of modern life.

While some were blaming technology for widespread health problems, others were embracing it as the ultimate cure—a paradoxical narrative that's still very much with us today. Today’s wearable devices remain, in many ways, an answer to long-held American anxieties about technology.

This is why, in an age when computers and the Internet have confined many American workers to sedentary desk jobs, wrist-worn exercise trackers can be seen as one response. It’s why the blue glow of a smartphone that keeps you up too late reading begets the sleep trackers that quantify insomnia. And it’s why fears about new parenthood are answered with sleek, wearable newborn monitors that show no evidence of actually keeping babies safer than they would be without them.

It’s not that all wearable devices are useless—just that our reasons for donning them haven’t changed all that much in more than a century. People still cloak themselves in the dazzling promise of new technology. They still tell themselves that peace of mind in a busy world is something you can wear like a shield, even if that shield won’t actually protect you.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.