QI: The Second Book of General Ignorance

by John Lloyd

  Attila’s personal style was modest in comparison to the gold-bedecked gangsters around him. He used wooden goblets and plates, dressed simply, and his sword carried no decoration. Not so his funeral. He was buried in a gaudy triple-walled coffin, with a layer each of gold, silver and iron, all of them stuffed full of treasure.

  He died somewhere in what is now Hungary, but his grave has never been found. To ensure its location remained secret, all the men in the burial party were killed when they returned to camp.

  What should you do when you get a nosebleed?

  Don’t tilt your head back!

  This can divert the nosebleed into the throat. Swallowing blood irritates the stomach and can lead to nausea and vomiting, or if it finds its way into the lungs it can choke you – as Attila the Hun found to his cost. The best treatment is to sit down with your back straight and lean forward. Keeping your head above your heart lessens the bleeding. Leaning forward helps drain the blood from your nose.

  According to the British Medical Journal you can stop the bleeding by using your thumb and index finger to squeeze the soft part of your nose for five to ten minutes. This helps the blood to clot. A cold compress or ice pack placed across the bridge of your nose also helps. If the nosebleed lasts for more than 20 minutes – or if it was caused by a bang on the head – you should go to the doctor.

  The scientific term for a nosebleed is epistaxis, which is Greek for ‘dripping from above’. The two most common causes of nosebleeds are being punched in the face and nosepicking. The web of blood vessels in your nose can also rupture owing to sharp changes in air pressure or temperature caused by cold weather or central heating, or if you blow your nose too hard.

  Almost all nosebleeds occur in the front section of the nose, under the nose bone or septum. This is known as Kiesselbach’s area, and it’s vulnerable because four facial arteries connect there. Wilhelm Kiesselbach (1839–1902) was a German ear, nose and throat specialist who wrote the definitive textbook on the subject called Nosenbluten (German for ‘nosebleeds’).

  High levels of the hormone oestrogen during a woman’s period can lead to an increase in blood pressure causing nasal blood vessels to inflate and burst. This is no mere nosebleed. It goes by the alarming name of ‘vicarious menstruation’.

  STEPHEN What are the commonest causes of nosebleeds?

  ALAN Bouncy castles.

  STEPHEN A classic, yeah. Another one is being punched in the face.

  What happens if you swallow your tongue?

  Nothing. It’s physically impossible to swallow your own tongue.

  The airway of an unconscious person can sometimes briefly become blocked as the muscle of their tongue becomes limp and it collapses into the back of their throat. However, it will return to its normal position in a few seconds. The tongue is kept in place by a small piece of tissue underneath called the frenulum linguae (from Latin frenulum, ‘little bridle’, and lingua, ‘tongue’), which stops it being swallowed.

  The idea that the tongue is in danger of being swallowed dates back to the early years of first aid in the late nineteenth century. First-aiders were taught that, if someone fainted or was having a fit, they should use forceps to pull the tongue forward, or, if none were available, to grab it with their fingers, using a handkerchief. Some well-meaning (but misguided) people still do this today, inserting pieces of wood – or even their wallets – into the mouths of people who are having fits. This is not a good idea. It stops the patient from being able to breathe.

  If someone faints, don’t start stuffing the contents of your pockets down their throat, put them into the recovery position: lay them on one side, with their chin tilted up so they can breathe clearly.

  Swallowing occurs about 2,000 times a day. Except for the initial conscious decision to do it, it is an automatic process that involves twelve separate muscle movements. Alzheimer’s patients and victims of strokes sometimes lose the ability to swallow. They are helped to relearn how to do it by speech therapists. This is because speech uses exactly the same combination of muscles as swallowing.

  When someone is close to death, the swallowing reflex often fails. This leads to a build up of saliva and mucus in the back of the throat, causing the so-called ‘death rattle’. Before writing the patient off, however, check their airway for wallets.

  Which part of your tongue tastes bitter things?

  All of it.

  The ‘tongue map’, once widely taught in schools, purported to show how each area of the tongue was solely responsible for one of ‘the four basic tastes’ – sweet, sour, bitter and salty. In fact, this is quite wrong. Wherever you have taste buds – all over the tongue and the roof of the mouth – you can detect all tastes more or less equally. Plus, there are more than four basic ones.

  According to the tongue map, the tip of the tongue tasted sweet things and the back, bitter ones. The sides of the tongue at the front were for tasting salt while the sides at the back did sour. The map was based on German research published in 1901 but an influential Harvard psychologist with the unfortunate name of Edwin Boring (1886–1968) mistranslated it. What the original research had shown was that the human tongue has areas of relative sensitivity to different tastes – but Boring’s translation stated that each could only be tasted in one zone.

  What is really mysterious about the tongue map is that it was the official truth for such a long time, even though it’s so easily disproved. (Just put some sugar on the part of your tongue that the map says tastes only salt.) It wasn’t until 1974 that another American scientist, Dr Virginia Collings, re-examined the original theory. She showed that, though sensitivity to the four main tastes did vary around the tongue, it was only to an insignificant degree. She also demonstrated that all taste buds taste all tastes.

  The other myth the tongue map perpetuated was that there are only four basic tastes. There are at least five. Umami is the taste of protein in savoury foods such as bacon, cheese, seaweed or Marmite. It was first identified by Professor Kikunae Ikeda, professor of chemistry at Tokyo University, as long ago as 1908, but was only formally confirmed as the ‘true’ fifth taste in 2000 when researchers at the University of Miami discovered protein receptors on the human tongue.

  ‘Umami’ is derived from umai, the word for ‘tasty’ in Japanese. Professor Ikeda found out that its key ingredient is monosodium glutamate, now known as MSG. Ikeda was shrewd – he sold his recipe for it to the Ajinomoto Company, which still holds one third of the 1.5-million-ton global annual market for synthetic MSG.

  Given the importance of protein in our diet, it makes sense for umami to stimulate the pleasure centre of our brains. A robust, mature red wine, for example, has an ‘umami’ taste. A bitter taste, by contrast, alerts us to the possibility of danger.

  ‘Taste’ shouldn’t be confused with flavour, which is a broader experience involving not just taste, but also smell, sight, touch and even hearing (it’s thought that the sound of crunchy food contributes to its flavour).

  Lexical-gustatory synaesthesia is a rare condition whereby taste and language are confused in the brain, so that each word has a specific taste. In one experiment a woman tasted tuna whenever she thought of the word ‘castanet’.

  What does cracking your knuckles do?

  Don’t worry: it won’t cause arthritis. At worst, it might leave you with a limp handshake.

  We know this because of the selfless dedication of Dr Donald L. Unger, an octogenarian physician from California. Warned as a child by his mother that if he didn’t stop cracking his knuckles he would end up with arthritis, he embarked on an experiment, cracking the knuckles of his left hand (but not those of his right) every day for more than sixty years. His conclusion was that knuckle-cracking had no serious effect. At the end of the experiment, he claims, he ‘looked up to the heavens and said: “Mother, you were wrong, you were wrong, you were wrong.”’ His efforts won him the 2009 IgNobel prize for Medicine, a parody of the Nobel Prize started in 1991 and awarded annu
ally for improbable research that ‘first makes us laugh and then makes us think’.

  This is not to say that knuckle-cracking is entirely harmless: it can make your joints swell and inflame your ligaments, and, over time, can reduce the strength of your grip.

  Our finger joints, like most moving joints in our bodies, are called synovial joints because they contain a strange liquid called synovial fluid whose job is to cushion and lubricate the joint. But it doesn’t ‘flow’ as most bodily fluids do: it has a thick, gel-like consistency, rather like egg white (hence the word synovial, from the Greek syn-, ‘with’, and Latin ovum, ‘egg’). Between each joint is a capsule, filled with synovial fluid and sealed by a membrane. When you pull the bones apart, the membrane stretches. This reduces the pressure inside the capsule and, as the fluid moves to fill the vacuum, bubbles of carbon dioxide form. The ‘pop’ that we hear is the bubbles forming (not bursting) inside the capsule.

  If you X-ray a joint just after it has been cracked, the bubbles of carbon dioxide are clearly visible. The joint can’t be cracked again until they’ve dissolved back into the fluid, which explains why you can’t crack the same knuckle repeatedly.

  The cracking of knuckles (and the creaking of joints) has a scientific name: crepitus, from the Latin crepare, ‘to crack’.

  Arthritis comes from the Greek arthron, ‘joint’, and -itis, a suffix denoting ‘inflammation’. It’s been around as long as animals have had articulated skeletons (there is evidence that some dinosaurs’ ankle joints were arthritic). The first evidence of human arthritis can be found in ancient Egyptian mummies that date back to 4500 BC.

  Arthritis comes in over a hundred different forms and afflicts all ages and ethnic groups. After stress, it’s responsible for more lost working days in the UK than any other medical condition, at an estimated annual cost of £5.8 billion. A quarter of all adult Britons consult their GP each year with arthritis-related complaints.

  Cracked knuckles are responsible for none of them.

  What are the symptoms of leprosy?

  In the popular mind, lepers have rotting flesh and parts of their bodies drop off.

  It doesn’t work like that. Leprosy – or Hansen’s disease as it’s now called – is an infectious bacterial disease that affects the skin and damages nerve-endings. This means that sufferers can’t feel pain and so repeatedly injure their fingers and toes. Over time these wounds become infected and leave disfiguring scars.

  It is these injuries, not the disease itself, that cause the deformities leprosy is famous for. People can live into old age with the disease as it doesn’t attack vital organs but, left untreated, it can cause crippling disabilities and even blindness.

  Leprosy is from the Greek lepros (‘scaly’). Ironically, it comes from the same root as the word Lepidoptera (‘scale wings’), the scientific name for butterflies. For many centuries, the word ‘leprosy’ was used indiscriminately to cover a broad range of disfiguring skin diseases. A ‘leper’ might just as easily have been someone with a bad case of psoriasis. It wasn’t until 1873, when the Norwegian physician Gerhard Armauer Hansen (1841–1912) identified Mycobacterium leprae as the cause of leprosy, that its accurate diagnosis was possible. Hansen’s discovery was groundbreaking. It was the first time a bacterium had been proven to cause a disease in humans.

  Until this point, it had been assumed that leprosy was hereditary because, despite its scary reputation, it’s quite difficult to catch. About 95 per cent of people are naturally resistant to the bacterium, and even those who aren’t require prolonged close contact to become infected. In 1984, to get this point across, Pope John Paul II kissed a number of lepers in a South Korean leper colony.

  The good news is that Hansen’s disease has been treatable with antibiotics since 1941. Over the last twenty years, 15 million patients have been cured but there are still some 250,000 new cases a year, and a million people worldwide are receiving, or are in need of, treatment. In 2009 121 countries recorded cases of leprosy. Even the USA recorded 150 and the UK twelve. More than half of all new cases are reported in India. Although 150,000 new cases a year sounds high, this is an infection rate of less than 1 in 10,000. According to World Health Organization standards, this officially qualifies leprosy for ‘eliminated’ status.

  Europe’s only remaining leper colony is in Tichilesti in Romania. In 1991 the colony was opened and residents were free to leave. Many of them had known nothing else since childhood and decided to stay on: the colony is more like a village than a hospital, with its own farm, two churches and even a vineyard,

  Leprosy is a rare example of a bacterial disease that almost exclusively attacks humans: the only other animals that can catch leprosy naturally are chimpanzees, mangabey monkeys and nine-banded armadillos.

  Why did lepers start carrying bells?

  Leper’s bells were designed to attract people, not to keep them away.

  From the earliest times, lepers were forced to live separately. In Europe they were legally forbidden to marry, make a will or appear in court – and were only allowed to talk to a non-leper if they stood downwind. In the Old Testament, God himself instructs Moses to ‘put out of the camp every leper’.

  This was because leprosy was regarded as a punishment rather than an infectious disease: it was an outer ‘uncleanness’ caused by inner sin, something that God would smite you with if you harboured lustful or heretical thoughts. It was the priest, not the doctor, who declared you a leper.

  In the early twelfth century two things happened to change this attitude. The first was that a number of Christian soldiers returning home from the First Crusade of 1099 were found to have picked up the disease. The second was a shift in the theological consensus concerning a key passage in the Bible. Referring to the Messiah, the prophet Isaiah wrote: ‘We did esteem him stricken, smitten of God, and afflicted.’ The Hebrew for ‘smitten’ is nagua. When some unknown Biblical scholar realised that everywhere else the word occurs in the Old Testament it means specifically ‘smitten with leprosy’, the inescapable conclusion was that Isaiah had predicted Jesus would suffer on our behalf by being treated like a leper.

  The effect was to rebrand leprosy as a ‘holy disease’. The stricken Crusaders, far from being punished, were being marked out by God for special reward. St Francis of Assisi (1182–1226) overcame his revulsion to embrace a leper and made the care of lepers a central part of the monastic order he founded. Henry I’s daughter, Matilda (1102–67), established a hospital for lepers at Holborn in London and publicly washed and kissed their feet. All over Europe monarchs and aristocrats competed with one another to endow leper colonies.

  Lepers themselves were granted special privileges: the most important being the right to beg. In some places they were entitled to a fixed portion of all the produce sold on market day. For 200 years, although they lived separately, they mingled freely at shrines and travelled on pilgrimages. This was when the practice of lepers carrying bells and rattles started. They were used, not to warn people away, but to attract donations from them: helping a leper was a sacred act.

  Attitudes hardened again after the Black Death (1348–50) – the plague was sometimes called ‘a leprosy’ – but, by the mid-fifteenth century, it hardly mattered: lepers had all but disappeared from Britain.

  Lepers were particularly vulnerable to bubonic plague and tuberculosis (the TB bacterium is leprosy’s closest bacterial relative). As waves of infectious diseases spread across Europe in the fourteenth and fifteenth centuries, the lepers’ already weakened immune systems succumbed first. Their numbers declined; soon there were too few of them left to spread the disease and their bells stopped ringing for good.

  STEPHEN Why did lepers carry bells?

  ALAN They were doing an act, you know, one of those bell-ringing acts. For ‘A Leper’s Got Talent’.

  Who wore horned helmets?

  Not Viking warriors but Celtic priests.

  None of the horned helmets discovered in Europe by archaeologis
ts can be dated to the Viking Age (AD 700–1100). Most are Celtic and were produced during the Iron Age (800 BC–AD 100), including the famous helmet found in the Thames in the 1860s and now displayed in the British Museum. The lightness of its metal and its fine decoration strongly suggest that the Thames helmet must have been worn for ceremonial occasions rather than in battle. To a modern observer, the ‘horns’ are more like the cones on Madonna’s famously pointy bra.

  Technically speaking, the only authentic Viking helmet ever found dates from the tenth century AD (though it’s in the same style as the pre-Viking Vendel period helmets). Made from iron plate, it was found inside the burial mound of a Viking chieftain and resembles a peaked cap with built in eye-protectors that look like iron-rimmed specs. But there’s not even a hint of a horn. It’s likely that only senior Vikings wore metal helmets, if they wore them at all. The surviving illustrations from the period show most warriors wearing simple leather skullcaps or fighting bareheaded.

  The association of horned helmets with Vikings dates back no further than the nineteenth century, a period when many imperial European nations were re-inventing their mythic heritage. In Britain Druids and the Arthurian legends were all the rage; the Germans were lapping up operas about medieval Teutonic knights; and, not to be outdone, Scandinavians were dusting off their Old Norse sagas. In one of these, a republished edition of Frithiof’s Saga, a Swedish illustrator called Gustav Malmström included small horns and dragon wings on the hero’s headgear.