"Then I hope I'm an adequate replacement," Theo said, with a teasing grin. "It's like cleaning your cauldron properly between potions. You won't get the right reaction if there's anything left over." Chemistry and potions had more in common than Theo had been aware of when starting these experiments.
Theo grinned again. "I do know what guns are, and we have things like fireworks and other explosive items, we just don't call it gunpowder," he said, then reached out to take the coins from Senku. "So, toss these into the fire at the base just like the salt?"