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Dry-Cleaning 1

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57589.  Tue Mar 07, 2006 3:34 am Reply with quote


This question has no real ‘right’ answer(s). It is intended to elicit anecdotes from the panel about interesting stains etc. Stephen should give points (if any) as he sees fit.


Can you tell me something quite interesting about dry-cleaning?




Some Quite Interesting Things About Dry-Cleaning

1. Perhaps the most obviously QI thing about ‘dry’ cleaning is that it is not dry. Clothes are wetted just as they are with washing – but with chemical solvents rather than with water.

2. For some bizarre reason, there is no entry for ‘dry-cleaning’ in the Encyclopaedia Britannica. (Well, maybe there is on-line – I can be bothered to subscribe – but there certainly wasn’t one in the hard copy version when they had one).

3. In 1997, Stephen Zinder of Cornell University discovered bacteria that thrive in dry-cleaning fluid. The Dehalococcoides bacterium was originally found in a sewage treatment plant and it is thought to have adapted itself to take advantage of the polluted environment. Different strains are able to ‘breathe’ (and to break down) various kinds of chlorine-based toxic chemicals.

Picture ideas:


I think we should take a stills camera out into London and just shoot loads of dry-cleaning shops (see how many we can get in a morning...)


The chemical solvent used in dry-cleaning is perchloroethylene, commonly known as "perc". Unlike the petroleum and benzene based solvents used in the early, dangerous days of dry-cleaning, ‘perc’ is non-flammable and non-combustible, of “relatively” low toxicity, and can be efficiently reused and recycled. It takes 8-10 gallons of perc to clean 100lbs of clothes.

Perchloroethylene is classed as a hazardous waste. Opinions vary as to how dangerous it is to those who operate dry-cleaning machines. It causes liver tumours in mice (but not in rats) but it doesn’t harm the ozone layer (or cause smog).

There are over 34,000 high-street dry-cleaners in the USA.

About 161,000 metric tonnes of perc were used in the US in 2004. Only 12% of this was used for dry-cleaning. 66% is used in the manufacture of hydrofluorocarbons (an ozone-safe alternative to chlorofluorocarbons or CFCs).

Links to:




It is commonly stated all over the internet that dry-cleaning began in the 1820s when a man called Jolly Belin knocked over a lamp containing kerosene, noticed that it removed stains from a tablecloth and started the first commercial dry-cleaning shop in Paris in the 1840s.

This can’t be true because kerosene (aka paraffin) was not manufactured till 1859 (by George Henry Bissell).

More likely sources suggest that the lamp was in fact full of camphene (distilled turpentine); the man who knocked it over (supposedly in 1825) was a cloth dyer called Jean-Baptiste Jolly; what he spilled it on is variously given as either a tablecloth or his wife’s dress; he started the shop “Jolly-Belin” (probably in 1855) with his son-in-law (whose surname was Belin).

Records show that turpentine had been used for spot cleaning oily stains since 1720.

s: BID s: vns s:

Last edited by JumpingJack on Wed Mar 29, 2006 6:30 pm; edited 3 times in total

57638.  Tue Mar 07, 2006 5:36 am Reply with quote

And don't forget the neutrino thing. As you know:
A solar neutrino was expected to produce radioactive argon when it interacts with a nucleus of chlorine. Davis developed an experiment based on this idea by placing a 100,000-gallon tank of perchloroethylene, a commonly used dry-cleaning chemical and a good source of chlorine, 4,800 feet underground in the Homestake Gold Mine in South Dakota and developing techniques for quantitatively extracting a few atoms of argon from the tank.

Frederick The Monk
57672.  Tue Mar 07, 2006 6:50 am Reply with quote

Here's the website for the Sudbury Solar neutrino observatory in Ontario.

57677.  Tue Mar 07, 2006 6:58 am Reply with quote

To log it, this question was proposed as well:

What use did Ray Davis have for 100,000 gallons of dry-cleaning fluid in 1964?

Molly Cule
61113.  Tue Mar 21, 2006 5:25 am Reply with quote

When do spies dry clean?

When they think they are being watched. Dry clean is espionage speak for an action that agents take to see if they are under surveillance.

For example, a driver must make a sudden U-turn to see if a following car does the same. In sophisticated surveillance practices, such dry cleaning is expected. A subject may, for example, be followed by several cars on parallel routes. The U-turn would be picked up by a second car.

Other espionage words include –

Baby sitter – a body guard
Birdwatcher – British Intelligence word for a spy
Cobbler – spy who creates false passports, visas, diplomas and other documents.
Dangle – a person who approaches an intelligence agency with the intent of being recruited to spy against his own country.
Floater – person used only once or even unknowingly for an intelligence operation.


Some Navajo spy terms are.. –(Navajo means knife in Spanish) – did they fight with knives?
Da-he-tih-hi – or hummingbird – meant fighter plane
Besh-lo or iron fish meant submarine

62121.  Mon Mar 27, 2006 12:00 pm Reply with quote

I will start a separate thread for the neutrino thing.

I also like Molly's dry-cleaning spies, which ought to stand up as a separate question imho.

How about:

What do birdwatchers use dry-cleaning for?


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