“In the iron mortar,” said his mother. “Dorothy will give it to him.”
“And when they are all ready,” continued Rollo’s father, “come and tell me.”
Accordingly, immediately after tea, Rollo and James went out to give Jonas the directions about preparing the materials. Dorothy gave Jonas the mortar. She also brought out three tea-cups, and put them upon the kitchen table. Jonas picked up from the corner of the fireplace a few small coals, and put them into the mortar and then, took up the pestle.
“O, more,” said Rollo; “we want more than that.”
“Yes,” said Jonas; “but we must take a little at a time.”
“Why?” asked Rollo.
“Because,” replied Jonas, “if I put much into the mortar at once, I can’t make it fine. I must only have a little, and then the pestle and the bottom of the mortar come close together, and so it grinds up the smallest pieces.”
When Jonas had pounded up the charcoal which he had put in at first, he poured the black powder out into one of the tea-cups, and then put in more charcoal, which he powdered as before. He proceeded in this way until he had filled one of the tea-cups nearly half full. He then washed out the mortar, and put it down to the fire to dry. Then he took a glass jar, which Dorothy had brought him from the closet, and which was nearly full of a substance which looked like salt, and poured some of it into the mortar.
“Is that the saltpetre?” said Rollo.
“Yes,” replied Jonas.