when did the chinese first use gunpowder as a weapon
History of gunpowder At this point the formula contained too little saltpeter (about 50%) to be explosive, but the mixture was highly flammable, and contemporary weapons reflected this in their deployment as mainly shock and incendiary weapons. One of the first, if not the first of these weapons was the fire arrow.[13] The first possible reference to the use of fire arrows was by the Southern Wu in 904 during the siege of Yuzhang, when an officer under Yang Xingmi by the name of Zheng Fan (鄭璠) ordered his troops to "shoot off a machine to let fire and burn the Longsha Gate," after which he and his troops dashed over the fire into the city and captured it, and he was promoted to Prime Minister Inspectorate for his efforts and the burns his body endured.[14] A later account of this event corroborated with the report and explained that "by let fire (飛火) is meant things like firebombs and fire arrows."[13] Arrows carrying gunpowder was possibly the most applicable form of gunpowder weaponry at the time, as early gunpowder may have only produced an effective flame when exposed to oxygen, thus the rush of air around the arrow in flight would have provided a suitable catalyst for the reaction.[13]
Chemical weapons in World War I The first instance of large-scale use of gas as a weapon was on 31 January 1915, when Germany fired 18,000 artillery shells containing liquid xylyl bromide tear gas on Russian positions on the Rawka River, west of Warsaw during the Battle of Bolimov. However, instead of vaporizing, the chemical froze and failed to have the desired effect.[8]