Fireworks (colored fireworks)

In regards to colored fireworks, this was derived and developed from earlier (possibly Han or soon thereafter) Chinese application of chemical substances to create colored smoke and fire. Such application appears in the Huolongjing (14th century) and Wubeizhi (preface of 1621, printed 1628), which describes recipes, several of which used low-nitrate gunpowder, to create military signal smokes with various colors. In the Wubei Huolongjing Ming, completed after 1628, two formulas appears for firework-like signals, the sanzhangju and baizhanglian , that produces silver sparkles in the smoke. In the Huoxilüe by Zhao Xuemin, there are several recipes with low-nitrate gunpowder and other chemical substances to tint flames and smoke.