Zheng-tong: Year 4, Month Intercalary 2, Day 14
28 Mar 1439
The Yun-nan Provincial Administration Commission memorialized: "The expeditionary force against Lu-chuan will require vast quantities of grain. The amounts stored and transported are insufficient. In the existing regulations, the price of salt used for purchasing grain is too high and therefore there are few middle-men willing to supply grain for salt. Permission is thus requested to send the silver and paper money held in this office to Jin-chi and Da-li to purchase grain in preparation. It is further requested that, at Da-li, the price of salt at Hei-yan and the other wells, a total of four wells, be reduced from the current two shi of grain per yin of salt to one shi five dou per yin, and that, at Jin-chi, the price of salt at An-ning and Wu-jing be reduced from the current one shi two dou per yin of salt to one shi per yin. At Hei Well and Bai Well, the current price of one shi per yin should now be reduced to eight dou per yin." This was approved.
Zhong-yang Yan-jiu yuan Ming Shi-lu, volume 24, page 1000