As early as the Han Dynasty Chinese alchemists had succeeded in preparing red mercury oxide (HgO) by heating mercury in air with slow fire or by heating a mixture of lead red (Pb_3O_4) and mercury in a closed cauldron.

• 早在汉代,中国炼丹家们已经通过对水银的低温焙烧或在密闭的土釜中加热水银与铅丹的混合物,而得到了氧化汞。