The “Disease” That Struck Medieval Church Organs

The “Disease” That Struck Medieval Church Organs

Thanks to Brilliant for supporting this episode
of SciShow. Go to to learn more. [ ♪INTRO ] During long, cold winters in medieval Europe,
there was something weird going on with church organs. Across the continent, some of these instruments
were getting what people at the time called “tin leprosy” or “tin pest.” The organs grew gray, sickly-looking circles
that spread over time and made the pipes hard and brittle. Eventually, many of them fell
apart. But tin pest isn’t actually a sickness — or,
as people once thought — the work of the devil. It’s actually just some pretty simple
chemistry. It all comes down to the fact that a lot of
organ pipes, even now, are made with tin, since it can produce bright, resonant tones.
And it’s pretty and shiny. At least, sometimes. The thing is, tin exists in two different
forms, or phases, depending on the temperature. It’s a lot like how water can be liquid
at room temperature and solid when it gets cold. Except, instead of going from liquid to solid,
tin goes from one type of solid to another. Above 13.2 degrees Celsius, tin is a white,
shiny, strong metal. That’s the form of tin that people use to make organ pipes. But below that temperature, tin becomes dull,
gray, and easy to break. That’s the form those pipes were transforming into during
those long, cold winters. The reason these two forms are so different,
even though they’re both tin, is because of the way the atoms arrange themselves in
each phase. In white tin, atoms are arranged in what’s
called a tetragonal, or rectangular, structure. But in gray tin, atoms are farther apart,
arranged in more of a cube shape that’s less sturdy. These two forms are called allotropes. And
you might be more familiar with this phenomenon than you think. A similar thing happens with carbon, which
can either take the form of graphite, like in your pencil, or a crystal-clear diamond,
all depending on how its atoms are arranged. When it comes to tin, though, the process
of turning from white to gray doesn’t happen overnight. In fact, it can take months or years of cold
temperatures for it to noticeably transform. This is because it doesn’t happen as soon
as temperatures drop to 13 degrees Celsius. Just below the transition temperature, there’s
not enough difference between the energy of white tin and the energy of gray tin to motivate
a transformation — unless something acts as a catalyst. But that energy difference
increases as temperature drops. Around -30 degrees Celsius, that energy difference
becomes significant, and transformation can happen much more easily. But! If it gets much colder than that, another
factor comes into play that makes a transformation less likely. See, white tin has to expand by about a quarter
to transition to the gray form, and it takes a lot of energy to get the process started. Except, as the temperature drops, the molecules
in tin vibrate slower, so they don’t have the energy to overcome the barrier that it
takes to start the phase change. That means that right around -30 degrees,
there’s sort of a sweet spot where the transition is most likely to happen. But even at an ideal temperature, tin takes
a long time to transform. It’s not like water, which quickly turns into ice as soon
as it’s cold enough. That’s because both phases of tin are solid,
so its atoms are locked up in tight lattices, and it takes a long time for them to rearrange
themselves. That’s why old tin organs weren’t just
collapsing constantly. It took a long cold winter for those tin pipes to start transforming. But once gray tin appears, it can spread really
quickly, like a rash. The expansion of the tin makes little cracks
in the metal, and that creates more exposed edges, where atoms are free to move around
and rearrange themselves. And before long, the atoms of the white tin
reorganize into the structure of gray tin. Luckily, now that we know what causes it,
the tin pest is easy to prevent. Just adding small amounts of other metals, like lead,
can keep tin atoms from moving around and changing form. And since a lot of organ pipes are made of
metal blends, many have been able to withstand the test of time. It turns out a lot of mysteries aren’t so
mysterious once you’ve figured out a little bit of the science behind them. And you can
build your science skills with the courses on Brilliant’s course on everyday physics is
all about the unexpected ways you interact with physics in your day-to-day life. By the end, you’ll learn how traffic jams,
bridges, and even axe-throwing are founded in physics. And there are dozens of courses to choose
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And as always, thanks for watching SciShow. [ ♪ OUTRO ]

100 thoughts on “The “Disease” That Struck Medieval Church Organs”

  1. Speaking of disease, your voice sounded different, like maybe you had a cold or something. Granted, I mostly know your voice from the quiz show, but it still sounded weird.

    I mean, when I heard your voice at the start, I didn't even realize it was you.

  2. 0:32 First, thank you for being diligent enough to provide sources.  However, I can't find in any of these articles any reference in the include sources to churches  assuming tin plague was the "work of the devil." After searching around, I found several sites that casually use this phrase without feeling the need to source a reference. However, what little I could find on medieval tin pipe organs, it seems that what was a higher concern was where the tin was sources (high quality "Cornwell Tin" vs. cheaper "German Tin" ). It seems that some organ builders would charge for using the more expensive Cornwell Tin but instead use the lowest quality German Tin and then pocket the money. So, in this case, I would agree that the eventual pipes failure would be caused by the root of all evil: the love of money … or as you put it "the work of the devil."

  3. That element is called stannum. Because it's symbol is Sn. SN like from…IDK…stannum. Not some pointless translation.

  4. Search "Grey Tin" or "Tin Pest" here on YT for videos of the transformation and see how bad it is for rigid structures made of Tin.

  5. After all these years I thought Shakespeare was writing about the "Tempest" when it was all really about alchemy of the "Tin Pest".

  6. And so modern metallurgy repelled the work of the devil. It's such a tragedy when you realize how much religion has held back the advancement of civilization.

  7. Pure tin is never used in pipe organs nowadays. The the most common alloys are plain tin (75% tin, 25 % lead), used for bright clear sounds and for visible facade pipes, spotted metal (50% tin, 50 % lead), for most general purposes, common metal (30 % tin, 70%, lead) when a smoother warm sound is desired, and (rarely) Lead (94% lead, 6% antimony) for stopped pipes with a smooth sound. Sometimes copper and zinc is used. Copper works fine, zinc is quite useless but cheap. A lot of pipes are also made of wood, especially the really big ones. Organ building is a craft where science walk hand in hand with art.

  8. I wonder if this is applicable to bell bronze, which is traditionally comprised of 80% copper and 20% tin… This traditional bell bronze alloy is not only used for bells, but also professional grade musical cymbals…

  9. So, will the tin turn back into the regular (shiny, non-brittle) phase again, if it is left long enough in a hot temperature?

  10. This channel is lost I think. Not lost as in over, but it doesn't know what to do. Who is your audience?? Is it regular people that want some pop-science facts or is it science people that want scientific explanations for intricate phenomenon?
    Currently I see "fast fact" and think, oh this is some pop-science thingy, but then comes the explanation and there's actual scientific terms in it, that I doubt regular people without understanding of chemistry would understand easily..

  11. Meanwhile, in Orthodox Christianity of the Eastern Roman Empire:

    What organ? (i.e. musical instruments are traditionally not used for worship in Eastern Christianity)

  12. I can imagine why people were so superstitious and paranoid back then. imagine a metal instrument in your church suddenly sprouting bruises and then collapsing like they're made of rubber? kinda scar, definitely something to do with satan

  13. also these people were living in hell, the inside of your church is – 30 degrees CELSIUS, life was awful, I'd be religious too

  14. My church spent over a million dollars renovating our 200 century old pipe organ. I couldn’t understand how several of our pipes became so deformed. I actually thought it was some form of deliberate vandalism.
    THANK YOU, THANK YOU SO MUCH for explaining it to me.
    The international experts we hired to fix our organ could not explain it as well as you have here.

  15. Today I am grateful that I live in the modern days when I never have to worry about it being below freezing in a church or any other in-use building.

  16. Most pipes, like Principals and Diapasons, the main "organ" sound, are made with a lead and tin alloy. When the metal is done solidifying, it creates a beautiful mottled effect.

    Please contact your local organists to learn more. We love teaching people about this dying art.

  17. Very interesting, informative and such but ooooooh boy……. Is the comment section killing me laughing so hard! Had to stop reading because of lack of oxygen. My old weezing wind bellows can't support the amount of air needed to pump around my organ….ok I'll stop… Wind bellows? Stop? Organ? Anyone…? Ok I'll show myself out… I'll recompose myself (a new toccata! Haha! owdammitstopitalready)

  18. It also happens to iron (which is the main part of many steels) when it is heated up to a high enough temperature (around a 500 degrees C if I remember correctly). When this happen, the iron gets properties that are more like pure aluminium or gold – weaker and more malleable. This is why blacksmiths exists and why steel buildings can collapse during a fire.

  19. Iron does the same thing, which is why steel is possible. Iron only does it at an orange-hot temperature, hence smelting and forging and heat-treatment effects when carbon and other alloy elements are added.

  20. Not the work of the Devil, but the work of man, through ignorance of how they thought they could manipulate that which was made by God. But it truly was the abstract subtle influence, and power therein of the Devil that compelled man to go against God's plan. It is not everything we touch that crumbles, or everything that we create, but that which is compelled from sin. Even back then they had "Black Metal" organists.

    I'll see myself out…

  21. wrong. It was the work of the devil. In modern times we don't have this because religious scientists discovered new technologies that made these kinds of church organs obsolete. Just as Ken Hamm or Jeol Osteen or any of those extremely well respected religious multimillionaires. They have lots of money – and therefore are reaaalllly smart

  22. Of course no source given that they "blamed it on the devil". This I think is rather a myth and unfair stereotype about the old times.

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