floor of damp sand, and spread over it in a sheet. Presently, as the heat of the mass vaporized the water in the sand below, the sheet of litharge, still slightly fluid, began to heave and swell, and a number of small cones rose from its surface. Some of these cones reached the height of four inches, and then burst at the top, sending out a shower of red-hot fragments. I removed one of these cones when the litharge was cool. It had a regidar funnel-shaped crater, like that which Vesuvius had until three or four years ago.
The analogy is complete between these little cones and those on the lava-field at the foot of the volcano of Jorullo, the celebrated “hornitos;” the concentric structure of which, as described by Burkart, proves that they were formed in precisely the same manner. Until lately, the formation of the great cone of Jorullo was attributed to the same kind of action as the hornitos, but later travellers have established the fact that this is incorrect. One of the De Saussure family, who was in Mexico a few years back, describes Jorullo as consisting of three terraces of basaltic lava, which have flowed one above another from a central orifice, the whole being surmounted by a cone of lapilli thrown up from the same opening, from which also later streams of lava have issued.