Along with silk and paper, gunpowder is another invention by Chinese and the Silk Road helped it spread to the West. The dating of gunpowder is as early as 850 AD. The Chinese used gunpowder to make fireworks and for signal flares. Gunpowder was also thought to have been used in medicine and in alchemy(炼金术). This invention seems to have been discovered in China by accident —by alchemists when doing experiments.
The gunpowder used for military purpose was first recorded in 919 AD. By the 11th century, explosive bombs filled with gunpowder were introduced and used in China. The words "fire cannon" "rocket" and "fireball" appeared time and again in the official Song history as well as two other books written during the same period.
The first detailed description of using the "fire cannon" in warfare was in connection with a battle fought in 1126 when the Song army used it against the invading(入侵) enemy. The so-called " fire cannon" was a tube made of bamboo filled with gunpowder which, when fired, threw a flaming missile(投掷物) towards the enemy. According to a description of a battle scene in 1132. it took two persons to carry a "fire cannon", and the cannons were fired from a moving platform. And this platform had to be moved close to the wall of the besieged(被围攻的) city.
Gunpowder reached Japan, the Islamic countries and then Europe in the 13th century, and the Arabs improved gunpowder for military use. The early account of gunpowder in Europe was recorded by English philosopher Roger Bacon in the 13th century. One century later the Arabs used it to attack the Spanish town Baza and the next year in 1326 Florence ordered the manufacturing of cannon and cannon balls. From Italy the making of gunpowder soon spread to other European countries, and by the 1350s it had become an effective weapon on the battlefield.
