Wellcome Trust, Wikimedia Commons // CC BY 4.0
Wellcome Trust, Wikimedia Commons // CC BY 4.0

Fascinatingly Filthy: How Bad Science Saved Lives in Victorian London

Wellcome Trust, Wikimedia Commons // CC BY 4.0
Wellcome Trust, Wikimedia Commons // CC BY 4.0

If you’re a fan of science or history, you know that many of the most important discoveries in medicine were made due to wild speculation, lazy lab techs, or plain old accidents. And plenty of theories of healing were so wrong as to have actually been responsible for deaths, not cures. 

But every once in a while, humans of the past got lucky: Even though their science was completely wrong, the theory driving it saved lives anyway. Such is the case with “miasma,” a concept popular throughout the mid-1800s with laypeople, doctors, and public-health advocates.  

“The prevailing view was that ‘miasma’—foul smell, particularly the stench of rotting matter—was the cause of disease. It was an appealing idea—not least because the slums, where epidemics raged, stank,” says Lee Jackson, author of Dirty Old London, which recently came out in paperback. 

Mental_floss spoke to Jackson about how attempts to clean up the unbelievably filthy city in the 19th century—when the population increased tremendously—led to major improvements in both public and personal health that had a lasting legacy around the world. And it all happened despite the fact they didn’t have the science right. 


The true cause of disease—germs, or pathogens—wasn’t verified until Louis Pasteur conducted his experiments of the 1860s (though some scientists had proposed the idea much earlier), and it was another decade before the bacteria that cause tuberculosis, cholera, dysentery, leprosy, diphtheria, and other illnesses were identified and understood.

The Victorians made the classic error that correlation equals causation. Slums smell, due to poor sanitation, piles of garbage stacking up, and the lack of bathing and clothes-washing facilities; people in slums die of epidemics at a faster rate; ergo, stench causes disease.

And boy, did London stink. 

Let’s start with the dead bodies, which were buried in churchyards, most of them in the middle of neighborhoods. “Coffins were stacked one atop the other in 20-foot-deep shafts, the topmost mere inches from the surface. Putrefying bodies were frequently disturbed, dismembered or destroyed to make room for newcomers. Disinterred bones, dropped by neglectful gravediggers, lay scattered amidst tombstones; smashed coffins were sold to the poor for firewood,” Jackson writes in Dirty Old London.  

As the bodies, dead from old age or disease, rotted, pathogens leaked into the water table, sometimes making their way to nearby wells. But since germ theory wasn’t understood, it was the stench of the near-surface bodies that got the attention.

“London’s small churchyards were so ridiculously full, that decaying corpses were near to the top soil; ‘graveyard gases’ were a familiar aroma. In fact, gases from corpses are relatively harmless,” Jackson says. Large, open, park-like cemeteries were soon built on the outskirts of the city, relieving “miasma” and live bacteria from close proximity to drinking water. 

Sewage was another disease vector that seems obvious to the modern person, but to the people of the past, it was the gag-worthy smells wafting from privies that caused disease. In poor areas, up to 15 families—whole tenements—might be sharing one overflowing shack. Slumlords liked to cut corners by refusing to have the “night-soil men” come by for a pick-up; these workers would shovel the waste into buckets and haul it out to farms to be used as fertilizer, and they (understandably!) didn’t work for free. 

But sewage wasn't just a problem for those actually using the privies; the liquid that leaked into the water table from the privies also spread disease. Even in middle-class homes, solid waste accumulated in basement cesspools that slowly leaked liquid wastes into wells just feet away. 

“The building of a unified network of sewers in the 1850s–'70s undoubtedly saved London from further epidemics of cholera and typhoid. It was done on grounds of ‘miasma’ but, regardless, the consequences were very positive,” Jackson says. 


Public toilets were also finally built in the latter part of the 1800s, which cut down on street-stink—and also allowed women to have more freedom. Because only the poorest women and prostitutes peed in public (usually crouching over sewer grates to do so), lack of public facilities meant working-class women were often in a bind. These women “didn’t go out, or didn’t go’” according to Jackson’s research. “Navigating the city, therefore, required some level of planning, depending on your social class and whether you considered yourself ‘respectable’” Jackson says. (Like today, the bathrooms of shops or restaurants were generally only available to those making a purchase.)

Providing a place to pee also had the positive effect of cutting down on public urination by men. In some places the odor of urine, both fresh and old, was so intense that complaints to local councils were constant from the people who lived nearby. In some cases, the urine even degraded structures over time. Smart property owners installed “urine deflectors” on the sides of their buildings—if you were to aim your stream there, it would get bounced back onto your shoes. 

Public bathhouses—which often included spaces to wash and even dry laundry—also proved to be a boon to public health. It wasn't just about keeping bodies cleaner; for the poorest people in the city of London, water was only available from a public pump, and washing clothes and linens was often difficult-to-impossible. A place that allowed for washing of both body and textiles meant that diseases spread by fleas (such as typhus) were reduced. Bonus: Everyone smelled a bit better too.

Victorians went after that which stank—and public health improved. As Ruth Goodman writes in her book, How to Be a Victorian, “Housework was valuable in preserving health whichever theory you ascribed to. So too was community cleanliness: germs could be fought effectively as miasmas by good town management of waste, by regular street cleaning, by prosecuting those who dumped waste in public areas. Personal hygiene also had value with both germ and miasma theories of disease.” 

The Victorian era is now known as a great era of sanitation in Great Britain, with lasting changes and public infrastructure that still exists today. In a sense, it matters little that it was all based on something that didn’t exist.

7 Fast Facts About Animal Farting

Anyone who’s had a pet can testify that dogs and cats occasionally get gassy, letting rip noxious farts and then innocently looking up as if to say “Who, me?” You may not have considered the full breadth of animal life passing gas in the world, though—and not just mammals. In a new book, ecologist Nick Caruso and zoologist Dani Rabaiotti detail the farting habits (or lack thereof) of 80 different animals. Here are seven weird animal farting facts we learned from Does It Fart?.


A black-and-white illustration of a fish floating upside down on the surface of the water
Ethan Kocak

The diet of the Bolson pupfish, a freshwater fish found in northern Mexico, can lead to dangerous levels of gas. The pupfish feeds on algae, and it can inadvertently eat the gas bubbles that algae produces in warm temperatures. The air inflates the fish’s intestines and distends its belly, messing with its equilibrium and making it difficult to swim. Even if it tries to bury itself in sediment at the bottom of a pool, as Bolson pupfish are wont to do, the air causes the fish to rise to the surface, where it’s at risk of being eaten by a bird. If the fish doesn’t fart, it will likely die, either from predation or because its intestines rupture under the pressure of the trapped gas.


The Bolson pupfish isn't the only animal that needs healthy farts to maneuver underwater. Buoyancy is vital for swimming manatees, and they rely on digestive gas to keep them afloat. The West Indian manatee has pouches in its intestines where it can store farty gasses. When they have a lot of gas stored up, they’re naturally more buoyant, floating to the surface of the water. When they fart out that gas, they sink. Unfortunately, that means that a manatee’s ability to fart is vital to its well-being. When a manatee is constipated and can’t pass gas properly, it can lose the ability to swim properly and end up floating around with its tail above its head.


A black-and-white illustration of a termite farting
Ethan Kocak

They’re not as bad as cars or cows, but termites fart a lot, and because they are so numerous, that results in a lot of methane. Each termite only lets rip about half a microgram of methane gas a day, but every termite colony is made up of millions of individuals, and termites live all over the world. All told, the insects produce somewhere between 5 and 19 percent of global methane emissions per year.


Ferrets are quite the fart machines. They not only let ‘em rip while pooping—which they do every few hours on a normal day—but they get particularly gassy when they’re stressed. The pungent smells are often news to their creators, though. According to the book, “owners often report a confused look on their pet’s face in the direction of their backside after they audibly pass gas.” And you don't want your ferret to get really scared: Their fear response involves screaming, puffing up, and simultaneous farting and pooping.


A black-and-white illustration of a beaded lacewing standing triumphantly over a prone termite
Ethan Kocak

A winged insect known as the beaded lacewing carries a powerful weapon within its butt, what Caruso and Rabaiotti call “one of the very few genuinely fatal farts known to science.” As a hunting strategy, Lomamyia latipennis larvae release a potent fart containing the chemical allomone, paralyzing and killing their termite prey.


A black-and-white illustration of a whale farting above water while a woman on a boat speeds behind it
Ethan Kocak

As befits their size, whales produce some of biggest farts on the planet. A blue whale’s digestive system can hold up to a ton of food in its multiple stomach chambers, and there are plenty of bacteria in that system waiting to break that food down. This, of course, leads to farts. While not many whale farts have been caught on camera, scientists have witnessed them—and report them to be “incredibly pungent,” as Rabaiotti and Caruso tell it.


Octopuses don’t fart, nor do other sea creatures like soft-shell clams or sea anemones. Birds don’t, either. Meanwhile, sloths may be the only mammal that doesn’t fart, according to the book (although the case for bat farts is pretty tenuous). Having a belly full of trapped gas is dangerous for a sloth. If things are working normally, the methane produced by their gut bacteria is absorbed into their bloodstream and eventually breathed out.

The woodlouse has an odd way of getting rid of gas, too, though it’s technically not flatulence. Instead of peeing, woodlice excrete ammonia through their exoskeleton, with bursts of these full-body “farts” lasting up to an hour at a time.

The cover of 'Does It Fart?'
Hachette Books

Does It Fart? is available for $15 from Amazon or Barnes & Noble.

Can You Really Lose Weight by Pooping? It Depends on What You Eat

If you’re obsessed with either your scale or your bowel movements, you’ve probably wondered: How much of my weight is just poop? A teenage cousin of mine once spent an entire restaurant dinner arguing that he could lose up to 3 pounds if you just gave him a few minutes to sit on the toilet. As you might imagine, he was wrong. But not by that much, according to Thrillist, a site that’s been truly dominating the poop science beat lately.

You can indeed see the effects of a truly satisfying bowel movement reflected on your bathroom scale. (Wash your hands first, please.) But how much your feces weigh depends heavily on your diet. The more fiber you eat, the heavier your poop. Unfortunately, even the most impressive fecal achievement won't tip the scales much.

In 1992, researchers studying the effect of fiber intake on colon cancer risk wrote that the daily movements of poopers across the world could vary anywhere from 2.5 ounces to 1 pound. In their sample of 220 Brits, the median daily poop weighed around 3.7 ounces. A dietary intake of around 18 grams of dietary fiber a day typically resulted in a 5.3-ounce turd, which the researchers say is enough to lower the risk of bowel cancer.

A Western diet probably isn’t going to help you achieve your poop potential, mass-wise. According to one estimate, industrialized populations only eat about 15 grams of fiber per day thanks to processed foods. (Aside from ruining your bragging rights for biggest poop, this also wreaks havoc on your microbiome.) That's why those British poops observed in the study didn't even come close to 1 pound.

Poop isn’t the only thing passing through your digestive tract that has some volume to it. Surprisingly, your fabulous flatulence can be quantified, too, and it doesn’t even take a crazy-sensitive machine to do so. In a 1991 study, volunteers plied with baked beans were hooked up to plastic fart-capturing bags using rectal catheters. The researchers found that the average person farts around 24 ounces of gas a day. The average fart involved around 3 ounces of gas.

This doesn’t mean that either pooping or farting is a solid weight-loss strategy. If you’re hoping to slim down, losing a pound of poop won’t improve the way your jeans fit. Certainly your 24 ounces of gas won't. But to satisfy pure scientific curiosity, sure, break out that scale before and after you do your business. At least you'll be able to see if your fiber intake is up to snuff.

[h/t Thrillist]


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