武经总要
However it was not until the "Wujing Zongyao" that the exact chemical formulas for early Chinese gunpowder was revealed. The "Wujing Zongyao" contains three formulas for gunpowder: one for an explosive bomb launched from a trebuchet, another for a similar bomb with hooks attached so that it could latch on to any wooden structure and set it on fire, and another formula specified for a poison-smoke bomb used for chemical warfare.