 Poisonous gunpowder for hand-thrown or trebuchet launched bombs was created using a mixture of tung oil, urine, sal ammoniac, feces, and scallion juice heated and coated upon tiny iron pellets and broken porcelain.According to Jiao Yu, "even birds flying in the air cannot escape the effects of the explosion".Explosive devices include the "flying-sand divine bomb releasing ten thousand fires", which consisted of a tube of gunpowder placed in an earthenware pot filled with quicklime, resin, and alcoholic extracts of poisonous plants.