with the roots of the alpine grasses, enormous masses of rich red silver ore and threads of pure silver (in remolinos, clavos, and vetas manteadas). Another elevated plain west of the Purgatorio, near the Quebrada de Chiquera, is called "Choropampa" or the "Field of Shells" (churu, in the Quichua language, signifies shells, and particularly small eatable kinds, hostion, mexillon). The name refers to fossils which belong to the cretaceous group, and which are found there in such abundance that they early attracted the attention of the natives. This is the place where there was obtained near the surface a mass of pure gold spun round with threads of silver in the richest manner. Such an occurrence shows how independent many of the ores thrown up from the interior of the earth into fissures or veins, are of the nature of the adjacent rock and of the relative age of the formations broken through. The rock of the Cerro de Gualgayoc and of Fuentestiana has a great deal of water, but in the Purgatorio absolute dryness prevails. I found to my astonishment that notwithstanding the height of the strata above the level of the sea, the temperature of the last named mine was 15°.8 Reaumur (67°.4 Fahr.); while in the neighbouring Mina de Guadalupe the water in the mine showed about 9° Reaumur (52°.2 Fahr.) As in the open air the thermometer only rises to about 4° Reaumur (41° Fahr.), the miners, whose toil is severe, and who are almost without clothing, call the subterranean heat in the Purgatorio stifling.
The narrow path from Micuipampa to the ancient city of the Incas, Caxamarca, is difficult even for mules. The name
