Li Yu returned to the cellar and took out two baskets of saltpeter and some sulfur. She asked Old Madam Yun, Old Madam Xu, and the others to grind the saltpeter and sulfur separately into powder. Before they could grind them, Ji Xiang and Ruyi returned with the wine jar and iron sand.
When the two of them saw Li Yu rolling up her sleeves and pushing the mill, they hurriedly put down the wicker basket. Ji Xiang walked forward. "Madam, let us do it."
Ji Xiang looked at the saltpeter powder that Old Madam Yun and the others had sifted out. Ruyi asked Li Yu curiously, "Madam, is it useful for you to grind these things?"
Li Yu looked at the two of them. "It's very useful. When I'm done configuring it, I'll test it for you to see."
Ji Xiang looked at these things and was enlightened. "Are you going to use those wine jars to store these things? The cork won't be ready for another four hours!"
