Blue glass: the 19th-century miracle cure that split the country

Frederick Opper/Library of Congress

Why are absurdities like vaccine paranoia, Dr. Oz's miracle cures, and ads promising "Eight-Pack Abs" debated so fiercely? In a lot of cases, the debate becomes bigger than the craze itself — a proxy for how smart or dumb the people on each side are.

In the 1870s, a former Civil War general outdid every one of our 21st-century panaceas. Some people thought it was a solution for everything from ailing crops to ailing health; others thought the believers were morons. And both sides took every opportunity to shout at each other about it.

The miracle cure? Blue glass.

A former Civil War General starts an unlikely health craze

The founder of 1877's biggest health craze, Augustus James Pleasonton, was born to an elite Washington family in 1808, and from there he went on to West Point. He was never a likely medical leader — he was the type of person who, after fighting rioters in Philadelphia in 1844, had a musket ball permanently lodged in his groin for the rest of his life. While in his 50s, he served as brigadier general of Pennsylvania's volunteer militia in the Civil War.

But the entire time he was fighting, Pleasonton had a second passion: experimentation. His big epiphany was that the blue color of the sky had to have some connection to living organisms' success. He thought the fertile land near the equator was a product of the amazingly blue sky (it was enhanced by electricity in the upper atmosphere). The North and South Poles, in turn, had negative electricity and a harmful absence of ... blueness. Though Pleasonton name-checked Isaac Newton, his science took basic theories about color to extreme and absurd conclusions.

In 1860, he put his theories into action by building a grapery in West Philadelphia with alternating blue glass panes on the roof.

Pleasonton via Internet Archive

After a short period of time, he was completely convinced that grapes under blue-paned glass grew better than those under plain glass, and that drove him to further experimentation.

He raised pigs under violet and blue glass and said they grew better than the ones raised under standard glass. From there, he moved on to cows (he said his Alderney bull calf was "one of the best developed animals that can be found anywhere"). Encouraged by his success, Pleasonton secured a patent for his blue grapery design.

The idea caught fire when Pleasonton described it all in an 1871 talk and 1876 book, exhaustingly titled The Influence of the Blue Ray of the Sunlight and of the Blue Colour of the Sky, in Developing Animal and Vegetable Life; in Arresting Disease, and in Restoring Health in Acute And Chronic Disorders to Human and Domestic Animals. The book included testimonials from satisfied blue-glass users who claimed that blue light cured their maladies, and they helped turn blue glass into a frenzy.

In 1872, Pleasonton had offered his plan to physicians at Pennsylvania Hospital in Philadelphia, and use rapidly grew from there. As he explained in his book, that same year, a mother and premature baby were placed under blue-glass-tinted light. Pleasonton credited their recovery to the magic of the glass; he also published reports that claimed the glass had cured lower back pain, baldness, and insomnia.

The book haphazardly mixes jargon about light, electricity, the atmosphere, and the power of the color blue, but it still became a huge success. Thanks to the testimonials for the cure (a technique familiar to anyone who's seen a miracle cure ad today), Pleasonton's pet theory turned into a bona fide craze.

Blue glass split the country into believers and skeptics, and people loved arguing about it

Nebraska Advertiser/Library of Congress

By 1877, the blue glass craze had truly taken off. Enough people believed in the "science" of blue glass to make it a credible mania. Some newspapers covered the controversy behind the glass while refusing to discredit the method, while others, like the Chicago Tribune, earnestly reported on Pleasonton's discovery.

Many papers, however, riffed on how stupid blue glass was: they made the 19th-century equivalent of Twitter jokes about "the black and blue dress" or Gwyneth Paltrow's latest newsletter. The Detroit Press actually printed — and syndicated — lame jokes, including, "Gen. Pleasanton, in his efforts to introduce the new style of blue glass, has proved himself an exceedingly panes-taking gentleman." Other newspapers mocked the glass with jokes that people were putting blue glass in their shoes and parody stories about people who "blue their brains out."

The boom had sent blue glass prices soaring 50 percent. But within a few years, the fervor for blue glass had faded.

The blue glass craze isn't just a history of inferior science. It's about viral ideas.

What makes blue glass most interesting isn't that people believed something that was wrong. It's that one bad idea captured the entire country's attention for a whole year.

The craze fed on the believers and skeptics equally. Because blue glass could excite such passion, it didn't matter that the science behind it was bad. All that mattered was that it was interesting to talk about.

In 1877, when the fervor was at its hottest, the Boston Globe had the best analysis of the blue glass mania. It could work for any fad today, especially in an era of nonstop social media warfare:

Indeed we hope the epidemic will be violent and proportionally short. It is amusing to see people making fools of themselves, but it soon grows wearisome.

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