The Aztecs worked silver-mines here, as well as at Tasco, long before the Spaniards came, and they knew how to smelt the ore.

It is true that, if no better process than smelting were known now, most of the mines would scarcely be worth working; but still, to know how to extract silver at all was a great step; and indeed at that time, and for long after the Conquest, there was no better method known in Europe.

It was in this very place that a Spaniard, Medina by name, discovered the process of amalgamation with mercury, in the year 1557, some forty years after the invasion.

We went to see the place where he first worked his new process, and found it still used as a "hacienda de beneficio" (establishment for extracting silver from the ore.) So few discoveries in the arts have come out of Mexico, or indeed out of any Spanish colony, that we must make the most of this really very important method, which is more extensively used than any other, both in North and South America.

As for the rest of the world, it produces, comparatively, so little silver, that it is scarcely worth taking into account.
We had forgotten, when we went to bed, that we were nearly seven hundred feet higher than Mexico; but had the fact brought to our remembrance by waking in the middle of the night, feeling very cold, and finding our thermometer marking 40 degrees Fahr.; whereupon we covered ourselves with cloaks, and the cloaks with the strips of carpet at our bedsides, and went to sleep again.
We had hired, of the French landlord, two horses and a mozo to guide us, and sorry hacks they were when we saw them in the morning.