China was the home of alchemy . The invention of gunpowder was a by-product of alchemy , the primary purpose of which was to make elixir . Originally , gunpowder was used in China for making fireworks and fire crackers for the sake of amusement . Since the Five Dynasties it began to be used for military purposes . The “Chronicles of Nine Kingdoms” written by Lu Zhen (904 A.D.) recorded : Yang Xiangmi was a warlord occupying the Yangtze River and the Huai River valleys . His army besieged the city of Nanchang .

　　Zhen Fan , his lieutenant , projected flying fire to burn the city-gate and led the troops to enter the city . Fire scorched all his body . The “flying fire” was the gunpowder . In the Song Dynasty gunpowder was used widely in battles . “Summary of Warfare Classics” written by Zen Gongliang listed many gunpowder-charged weapons : the thorn fire ball , the smoky fire ball , the cannon , etc . Toward the end of the Northern Song Dynasty , weapons with even higher explosive power were made , such as “thunderbolt cannon” “sky shaking cannon” , etc .

　　The “sky shaking cannon” was then the standard iron cannon . Beside the cannons , firearms in barrel forms also appeared . Rifles and fast rifles were used in battles in the Song Dynasty ; these were improved on in the Yuan and Ming Dynasties . The continuously firing piece invented in the Ming Dynasty could shoot consecutively twenty eight bullets . It was the forerunner of the machine gun . The Chinese tradition of “keeping secrets within the home” has caused the gunpowder , a promising weapon , to sink into oblivion .
       After the thirteenth century , gunpowder spread gradually to Arabia , and then to Europe . It was a tremendous impetus to the progress of European history . The invention of gunpowder meant a far-reaching technological revolution that transformed heat energy into mechanic energy , greatly promoting the progress of the global civilization .