Even then, the way of making several implements or weapons is not entirely clear.  We got several obsidian maces or lance-heads—­one about ten inches long—­which were taper from base to point, and covered with taper flutings; and there are other things which present great difficulties.  I have heard on good authority, that somewhere in Peru, the Indians still have a way of working obsidian by laying a bone wedge on the surface of a piece, and tapping it till the stone cracks.  Such a process may have been used in Mexico.

We may see in museums beautiful little articles made in this intractable material, such as the mirrors and masks I have mentioned, and even rings and cups.  But, as I have said, these are mere lapidaries’ work.

The situation of the mines was picturesque; grand hills of porphyritic rock, and pine-forest everywhere.  Not far off is the broad track of a hurricane, which had walked through it for miles, knocking the great trees down like ninepins, and leaving them to rot there.  The vegetation gave evident proof of a severe climate; and yet the heat and glare of the sun were more intolerable than we had ever felt it in the region of sugar-canes and bananas.  About here, some of the trachytic porphyry which forms the substance of the hills had happened to have cooled, under suitable conditions, from the molten state into a sort of slag or volcanic glass, which is the obsidian in question; and, in places, this vitreous lava—­from one layer having flowed over another which was already cool—­was regularly stratified.

The mines were mere wells, not very deep; with horizontal workings into the obsidian where it was very good and in thick layers.  Round about were heaps of fragments, hundreds of tons of them; and it was clear, from the shape of these, that some of the manufacturing was done on the spot.  There had been great numbers of pits worked; and it was from these “minillas,” little mines, as they are called, that we first got an idea how important an element this obsidian was in the old Aztec civilization.  In excursions made since, we travelled over whole districts in the plains, where fragments of these arrows and knives were to be found, literally at every step, mixed with morsels of pottery, and here and there a little clay idol.  Among the heaps of fragments were many that had become weathered on the upper side, and had a remarkable lustre, like silver.  Obsidian is called bizcli by the Indians, and the silvery sort is known as bizcli platera.[11] They often find bits of it in the fields; and go with great secrecy and mystery to Mr. Bell, or some other authority in mining matters, and confide to him their discovery of a silver-mine.  They go away angry and unconvinced when told what their silver really is; and generally come to the conclusion that he is deceiving them, with a view of throwing them off the scent, that he may find the place for himself, and cheat them of their share of the profits—­just what their own miserable morbid cunning would lead them to do under such circumstances.