Application of toxic substances as a weapon began in the Spring-Autumn Period. In 677 B.C. the people of Sui dropped poisons into water to expel army from Qi State. During the period of cold weapon in addition to toxic fumigation, poisons were also spread on spears, swords and arrows. Recipes for anti-toxic arrows were recorded in Chen Yanzhi's Xiao-pin-fang of the Western Jin Dynasty, Liu Juan-zi's Gui-Yi-fang of the Liu-Song Dynasty, Jin-chuang-mi-chuan-jin-fang of the Yuan Dynasty. As a rule, toxication through natural sources were emphasized as described in Tai-bai-yin-jing of the Tang Dynasty, etc, including selection of camping sites, quality of water supply. It was also mentioned that the general of an army should despatch order for antitoxicity during travelling.