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.
Gunpowder was the first physical explosive and propellant. Prior to its invention, many incendiary and burning devices had been used, including Greek fire. The invention of gunpowder is usually attributed to Chinese alchemy, and is popularly listed as one of the .Four Great Inventions  of China.It was invented during the Tang Dynasty (9th century), and the earliest record of a written formula appeared in the Song Dynasty (11th century).Knowledge of gunpowder spread throughout the Old World as a result of the Mongol conquests of the 13th century.t was invented during the Tang Dynasty (9th century), and the earliest record of a written formula appeared in the Song Dynasty (11th century). Knowledge of gunpowder spread throughout the Old World as a result of the Mongol conquests of the 13th century.