《黄帝内经·素问·六元正纪大论》
阳气不得主治，阴气聚积于空中，白埃昏暗，这就是水郁开始发作的现象，发作时间，多在君火与相火即二之气主时的前后。
阳光不治，空积沉阴，白埃昏暝而乃发也。其气二火前后。
The positive qi cannot prevail, and negative qi accumulates in the air. The white dust is dim, which is the phenomenon of the beginning of water depression. The time of onset is often before or after the time when the monarch fire and the phase fire are the second qi.