Gout causes a painful, swollen joint that's so severe that the weight of bed sheets can cause distress. There may also be more than one joint affected with gout. With gout, uric acid -- a normal chemical in the body -- forms crystals that deposit in the joints, causing inflammation and pain.
China has been the source of many innovations, scientific discoveries and inventions. This includes the Four Great Inventions: papermaking, the compass, gunpowder, and printing (both woodblock and movable type). The list below contains these and other inventions in China attested by archaeology or history.
In 1267, a European writer made reference to gunpowder, and by 1280 the first recipes for the explosive mixture were published in the west. China's secret was out. Down through the centuries, Chinese inventions have had a profound effect on human culture. Items like paper, the magnetic compass, and silk have diffused around the world. None of those inventions, however, have had quite the impact that gunpowder has, for good and for bad.