What's the Origin of "Let the Cat out of the Bag"?

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The first documented use of the phrase in the sense of “revealing a secret" comes from a book review in a 1760 issue of The London Magazine, wherein the reviewer laments that, "We could have wished that the author had not let the cat out of the bag."

That, unfortunately, is about all we know for sure. There are two popularly cited origins for the phrase, but neither is very clearly recorded as leading to it.

The first origin story claims the phrase refers to the cat o’ nine tails, infamously used by the Royal Navy as an instrument of punishment aboard its ships. The whip’s nine knotted cords could scratch an undisciplined sailor’s back pretty badly, hence its feline nickname. The bag comes into play because the “cat,” being made of leather, had to be kept in a sack to protect it from drying out in the salty sea air and keep it flexible. Removing a whip from a sack doesn’t immediately seem to have anything to do with revealing a secret (that the lash was on board the ship and would be readily used shouldn’t have been a secret to any sailor), but if you think of “letting the cat out of the bag” as a revelation that results in a punishment, it makes a little more sense.

Urban legend clearinghouse Snopes.com rejects this origin based on the idea that “let the cat out of the bag” is recorded before “cat o’ nine tails,” but the whip’s nickname shows up in print earlier than they claim: in a 1695 play called Love for Love by William Congreve, it is used in a very clear reference to a lashing at sea. I can’t say the same thing about “let the cat out of the bag,” though, and haven’t been able to find any recorded use of it in a nautical context.

Or Maybe It Relates to Livestock Fraud

The other explanation for the phrase is that it was born from a ridiculous bit of livestock fraud. Supposedly, merchants would sell customers live piglets and, after putting a pig in a sack for easier transport, would sometimes swap the pig for a cat when the customer looked away. The buyer wouldn’t discover they’d been cheated until they got home and literally let the cat out of the bag. Again, I can’t find any recorded links between the phrase and livestock markets, or even much evidence that this sort of con was commomplace. (Pigs were definitely bagged for sale, though, and Richard Hill's Common-place Book from 1530 offers some advice to merchants that led to another idiom: “When ye proffer the pigge open the poke.”)

There’s a certain implausibility to the trick, too. Piglets big enough to be taken to market differ in size and build from domestic cats. I have a cat fat enough to have earned the name “Oink,” and even he looks svelte next to a suckling pig. Consider also that cats meow, and don’t oink. I can’t imagine enough people would have picked up their purchase and thought, “this sack seems a little light, and isn’t making the right noise, but I guess everything is normal,” to make this ruse work often enough that an idiom came from it. The Spanish equivalent of the phrase - dar gato por liebre, or “giving a cat instead of a hare” - at least implies an origin with an animal that makes more sense. Rabbits meant to be eaten are usually sold already slaughtered and skinned, and are similar enough in size and appearance to cats in the same circumstances.

So the true origin is a mystery, and we’re just going to have to borrow a page from Fox News on this: I reported, you decide. Which of the explanations are you going to be dropping into small talk this week?

Big Questions
What Do Morticians Do With the Blood They Take Out of Dead Bodies?

Zoe-Anne Barcellos:

The blood goes down the sink drain, into the sewer system.

I am not a mortician, but I work for a medical examiner/coroner. During an autopsy, most blood is drained from the decedent. This is not on purpose, but a result of gravity. Later a mortician may or may not embalm, depending on the wishes of the family.

Autopsies are done on a table that has a drain at one end; this drain is placed over a sink—a regular sink, with a garbage disposal in it. The blood and bodily fluids just drain down the table, into the sink, and down the drain. This goes into the sewer, like every other sink and toilet, and (usually) goes to a water treatment plant.

You may be thinking that this is biohazardous waste and needs to be treated differently. [If] we can’t put oil, or chemicals (like formalin) down the drains due to regulations, why is blood not treated similarly? I would assume because it is effectively handled by the water treatment plants. If it wasn’t, I am sure the regulations would be changed.

Now any items that are soiled with blood—those cannot be thrown away in the regular trash. Most clothing worn by the decedent is either retained for evidence or released with the decedent to the funeral home—even if they were bloody.

But any gauze, medical tubing, papers, etc. that have blood or bodily fluids on them must be thrown away into a biohazardous trash. These are lined with bright red trash liners, and these are placed in a specially marked box and taped closed. These boxes are stacked up in the garage until they are picked up by a specialty garbage company. I am not sure, but I am pretty sure they are incinerated.

Additionally anything sharp or pointy—like needles, scalpels, etc.—must go into a rigid “sharps” container. When they are 2/3 full we just toss these into one of the biotrash containers.

The biotrash is treated differently, as, if it went to a landfill, then the blood (and therefore the bloodborne pathogens like Hepatitis and HIV) could be exposed to people or animals. Rain could wash it into untreated water systems.

This post originally appeared on Quora. Click here to view.

Big Questions
Why Does Asparagus Make Your Pee Smell Funny?

The asparagus has a long and storied history. It was mentioned in the myths and the scholarly writings of ancient Greece, and its cultivation was the subject of a detailed lesson in Cato the Elder's treatise, On Agriculture. But it wasn't until the turn of the 18th century that discussion of the link between asparagus and odorous urine emerged. In 1731, John Arbuthnot, physician to Queen Anne, noted in a book about food that asparagus "affects the urine with a foetid smell ... and therefore have been suspected by some physicians as not friendly to the kidneys." Benjamin Franklin also noticed that eating asparagus "shall give our urine a disagreeable odor."

Since then, there has been debate over what is responsible for the stinky pee phenomenon. Polish chemist and doctor Marceli Nencki identified a compound called methanethiol as the cause in 1891, after a study that involved four men eating about three and a half pounds of asparagus apiece. In 1975, Robert H. White, a chemist at the University of California at San Diego, used gas chromatography to pin down several compounds known as S-methyl thioesters as the culprits. Other researchers have blamed various "sulfur-containing compounds" and, simply, "metabolites."

More recently, a study demonstrated that asparagusic acid taken orally by subjects known to produce stinky asparagus pee produced odorous urine, which contained the same volatile compounds found in their asparagus-induced odorous urine. Other subjects, who normally didn't experience asparagus-induced odorous urine, likewise were spared stinky pee after taking asparagusic acid.

The researchers concluded that asparagusic acid and its derivatives are the precursors of urinary odor (compared, in different scientific papers, to the smell of "rotten cabbage," "boiling cabbage" and "vegetable soup"). The various compounds that contribute to the distinct smell—and were sometimes blamed as the sole cause in the past—are metabolized from asparagusic acid.

Exactly how these compounds are produced as we digest asparagus remains unclear, so let's turn to an equally compelling, but more answerable question:


Remember when I said that some people don't produce stinky asparagus pee? Several studies have shown that only some of us experience stinky pee (ranging from 20 to 40 percent of the subjects taking part in the study, depending on which paper you read), while the majority have never had the pleasure.

For a while, the world was divided into those whose pee stank after eating asparagus and those whose didn't. Then in 1980, a study complicated matters: Subjects whose pee stank sniffed the urine of subjects whose pee didn't. Guess what? The pee stank. It turns out we're not only divided by the ability to produce odorous asparagus pee, but the ability to smell it.

An anosmia—an inability to perceive a smell—keeps certain people from smelling the compounds that make up even the most offensive asparagus pee, and like the stinky pee non-producers, they're in the majority.

Producing and perceiving asparagus pee don't go hand-in-hand, either. The 1980 study found that some people who don't produce stinky pee could detect the rotten cabbage smell in another person's urine. On the flip side, some stink producers aren't able to pick up the scent in their own urine or the urine of others.

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