A colourful bag of details

The following text is originally lifted from the trivia section of The Jakarta Post dated Tuesday, 31July 2007.

~Compiled from various sources~

• The little bags of netting for gas lanterns (called mantles) are radioactive - so much that they would set off an alarm at a nuclear reactor.
• The metal part at the end of a pencil is 20% sulphur.
• The average lead pencil will draw a line 56 kilometres long or write approximately 50,000 English words.
• Moisture, not air, causes super glue to dry.
• The aluminium ranks as one of the mose highly engineered products created by the Western civilisation.
• Though a brick wall and a plate glass window look quite different from each other, both of them are made from the same principal ingredient: sand.
• Until the 18th century, India produced almost all the world's diamonds.
• The ancient Egyptians thought it was good luck to enter a house left foot first.
• In the late 19th century, millions of human mummies were used as fuel for locomotives in Egypt where wood and coal was scarce, but mummies were plentiful.
• 20% of all publications sold in Japan are comic books.
• The first toothbrush with bristles were developed in China in 1498. Bristles were taken from hogs at first, later from horses.
• Though it is often associated today with Satanism, Christians once commonly used the pentagram to represent the five wounds of Jesus Christ.
• If you lace your shoes from the inside to the outside the fit will be snugger around your big toe.
• The earliest document in Latin in a woman's handwriting - from the first century AD - is an invitation to a birthday party.
• During conscription for WW2, there were nine documented cases of men with three testicles.
• Medieval knights put sharkskin on their sword handles to give them a more secure grip; they would dig the sharp scales into their palms.
• The world's youngest parents were eight and nine and lived in China in 1910.
• Each king in a deck of playing cards represents a great king from history; Spades - King David, Clubs - Alexander the Great, Hearts - Charlemagne, and Diamonds - Julius Caesar.
• Sound travels 15 times faster through steel than it does through the air.
• You can test a two way mirror by putting your fingernail on the surface - if there's space between the tip and the image, then it's a normal mirror, if not, it's two-way.