压大单小单大双小双口诀

简介：Your Highness, according to the method you mentioned, take forty taels of saltpeter, five liang and six qian of sulfur, and seven liang and two qian of willow charcoal. Finely grind them and dry them into granules. Use a sieve to sift out the rice grains that are the same size and use them. If they are too big or too small, will be discarded. Qin Ning reported.