Summary on Extraction of Bronze

　　Jintong Yaolue (Summary on Extraction of Bronze), written by Zhang Qian of the Northern Song Dynasty (960-1127), is a book on the method of extracting copper from the mineral water that contains copper.

　　During the Yuan Dynasty (1279-1368), Zhang Li, one of Zhang Qian's offspring, consecrated the book to the government. In the early Ming Dynasty (1368-1644), Wei Su made some annotations to the book, calling the extracting method in the book costs little, but produces much.