"Zinc is not found in a native state. This ore is in the form of an oxide, as it is called. In roasting, certain of the impurities are driven off in gases, and mixing it with charcoal or coke and then applying heat to the confined mass, causes the zinc to melt and finally go off into a gas, as we shall presently see."
After the heat had been applied for some time a white smoke began to appear at the mouth of the clay tube, and a little later a blue vapor appeared.
"Now bring that pan here, so we can catch it."
Soon the dripping commenced, and as it ran out and came into contact with the air, it turned into a solid, greyish color.
"This is what is called spelter, or the pig of zinc, and this is what is sold to refiners, who take out all the dross or impurities so it can be rolled or used for galvanizing iron, or for other purposes."
"I do not see how we can use this metal, now that we have it."
"You said the other night that you wished we had a better light."
"That was the reason I was so anxious to see whether we couldn't get some kerosene at the 'hole.'"
"As we didn't succeed in finding petroleum we shall have to depend on our zinc, I suppose."
"What, light out of zinc?"