"I take twelve times as much lead as there iss of the stone," he said.
"What is the lead for?" asked Nelly.
"The lead he will draw out of the stone all that are bad: you will see."
Then he put the powdered stone and the lead he had mixed together into a little clay cup, and covered it over with more of the fine-powdered lead. Then he put in a little borax.
"He helps it to melt," he said.
Then he went through into the back room, carrying this cup and two others which were standing on the table already filled with powder ready to be baked.
Rob and Nelly and the old man followed him. He opened the door of the little oven and looked in: it was glowing red hot. Then he took up each cup in tongs, and set it in the oven. When all three were in, he took some burning coals from the fire above, and put them in the mouth of the oven, in front of the cups.
"Dat iss dat cold air from door do not touch dem," he said. Then he shut the door tight, and said:—
"Now ve go back. Ve vait fifteen minute."
He held his watch in his hand, so as not to make a mistake. When the fifteen minutes were over he opened the oven-door to let a current of cool air blow above the little cups. Nelly stood on a box, as she had before, and looked in through the queer board with holes in it for the eyes. The metal in the little cups was bubbling and as red as fire. Rob tried to look, but the heat hurt his eyes so he could not bear it.