Why Do Coins Make Your Hands Smell Funny?

iStock/fotosipsak
iStock/fotosipsak

A lot of people assume that it's just the way that coins smell, and the odor is rubbing off on their hands, but you're not smelling the metal so much as you're smelling yourself. That funky scent is actually a human body odor created by the reaction of oils in the skin contact with objects that contain iron (a separate, but similar odor, is created when we touch copper). What we think of as a "metallic smell" is only metallic by association.

Here's how it works.

When you touch something made of iron, perspiration on your skin cause the iron atoms to gain two electrons, and these doubly negative iron atoms react with oils in the skin, forming several types of compounds called aldehydes and ketones. If you've gotten a whiff of formaldehyde while dissecting frogs in science class or wrinkled your nose at the smell of acetone in nail polish remover, then you know that these compounds have very strong, distinctive odors.

When German researchers captured and studied the chemical composition of vapors coming from the skin of people who had just handled iron objects, they found one compound, 1-octen-3-one, that has a particularly pungent fungus-meets-metal smell and is detectable by humans at very low concentrations. This compound may be the main component of the odor of your hands post-money-handling.

You might have noticed that a similar smell is produced when blood meets skin. That's because blood contains iron and these iron atoms go through the same reaction you're your skin as the atoms from coins, producing the same scent molecules.

In What Field Was Dr. Martin Luther King Jr. a Doctor?

Express Newspapers/Getty Images
Express Newspapers/Getty Images

Martin Luther King Jr. earned a doctorate in systematic theology from Boston University in 1955. He’d previously earned a Bachelor of Arts from Morehouse College and a Bachelor of Divinity from Crozer Theological Seminary. His dissertation, “A Comparison of the Conception of God in the Thinking of Paul Tillich and Henry Nelson Wieman,” examined the two religious philosophers’ views of God in comparison to each other, and to King’s own concept of a "knowable and personal" God.

In 1989, some three decades after King had earned his doctorate, archivists working with The Martin Luther King Papers Project discovered that King’s dissertation suffered from what they called a “problematic use of sources.” King, they learned, had taken a large amount of material verbatim from other scholars and sources and used it in his work without full or proper attribution, and sometimes no attribution at all.

In 1991, a Boston University investigatory committee concluded that King had indeed plagiarized parts of his dissertation, but found that it was “impractical to reach, on the available evidence, any conclusions about Dr. King's reasons for failing to attribute some, but not all, of his sources.” That is, it could have been anything from malicious intent to simple forgetfulness—no one can determine for sure today. They did not recommend a posthumous revocation of his degree, but instead suggested that a letter be attached to the dissertation in the university library noting the passages lacked quotations and citations.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

Who Is 'The Real McCoy'?

Inventor Elijah McCoy is may or may not be "The Real McCoy."
Inventor Elijah McCoy is may or may not be "The Real McCoy."
Ypsilanti Historical Society, CC BY-SA 4.0 via Wikimedia Commons

After taking a cool, carbonated sip of champagne from the Champagne region of France, you might say, “Ah, now that’s the real McCoy.” Sparkling wine from anywhere else is technically just sparkling wine.

The phrase “the real McCoy,” which can be used to describe any genuine version of something, has several possible origin stories. And while none of them mention champagne, a few do involve other types of alcohol.

According to HowStuffWorks, the earliest known recorded instance of the saying was an 1856 reference to whisky in the Scottish National Dictionary—"A drappie [drop] o' the real MacKay”—and by 1870, a pair of whisky distillers by the name of McKay had adopted the slogan “the real McKay” for their products. As the theory goes, the phrase made its long journey across the pond, where it eventually evolved into the Americanized “McCoy.”

Another theory suggests “the real McCoy” originated in the United States during Prohibition. In 1920, Florida-based rum runner Bill McCoy was the first enterprising individual to stock a ship with alcohol in the Caribbean, sail to New York, and idle at least three miles offshore, where he could sell his wares legally in what was then considered international waters. Since McCoy didn’t water down his alcohol with substances like prune juice, wood alcohol, and even turpentine, people believe his customers started calling his top-notch product “the real McCoy.” There’s no definitive proof that this origin story is true, but The Real McCoy rum distillery was founded on the notion.

There are also a couple other leading theories that have nothing to do with alcohol. In 1872, inventor Elijah McCoy patented a self-regulating machine that lubricated parts of a steam engine without the need for manual maintenance, allowing trains to run continuously for much longer distances. According to Snopes, the invention’s success spawned a plethora of poor-quality imitations, which led railroad personnel to refer to McCoy’s machines as “the real McCoy.”

Elijah McCoy’s invention modernized the transportation industry, but he wasn’t the only 19th-century McCoy who packed a punch. The other was welterweight champion Norman Selby, better known as Kid McCoy. In one story, McCoy decked a drunken bar patron to prove that he really was the famous boxer, prompting others to christen him “the real McCoy.” In another, his alleged penchant for throwing fights caused the press to start calling him “the real McCoy” to acknowledge when he was actually trying to win. And yet another simply suggests that the boxer’s popularity birthed so many McCoy-wannabes that Selby started to specify that he was, in fact, the real McCoy.

So which “the real McCoy” origin story is the real McCoy? The 1856 Scottish mention of “the real MacKay” came before Elijah McCoy’s railroad invention, Kid McCoy’s boxing career, and Bill McCoy’s rum-running escapades, but it’s possible that the phrase just gained popularity in different spheres at different times.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER