444 
VEINS OF QUARTZ. 
uicates, by the valleys of Tacagua and of Tipe, with the 
coast near Catia. A ridge of rock, the summit of which is 
forty toises above the bottom of the valley of Caracas, and 
more than three hundred toises above the valley of Taca<ma. 
divides the waters which flow into the Eio Guayra and 
towards Cabo Blanco. On this point of division, at the 
entrance of the branch, the view is liighlv pleasing. The 
climate changes as we descend westward'. In the valley 
ot Tacagua we found some new habitations, and also eonucos 
ot maize and plantains. A very extensive plantation of 
tuna, or cactus, stamps this barren country with a peculiar 
character. _ The cactuses reach the height of fifteen feet, 
and grow in the form of candelabra, like the euphorbia of 
Africa. They are cultivated for the purpose of selling their 
refreshuig fruits in the market of Caracas. The variety 
which has no thorns is called, strangely enough, in the colo- 
nies, tuna de Uspaita (Spanish cactus). \Te measured, at 
the same place, magueys or agaves, the long stems of which, 
laden with flowers, were forty-four feet high. However 
common this plant is become' in the south of Europe, the 
native of a northern climate is never weary of admiring the 
rapid development of a liliaceous plant, which contains at 
once a sweet juice and astringent and caustic liquids, em- 
ployed to cauterize wounds. 
We foimd several veins of quartz in the valley of Tipe 
visible above the soil. They contained pyrites, carbonated 
non-ore, traces of sulphuretted silver (glasserz), and grey 
copper-ore (falilerz). The works which had been under- 
takeu, either for extracting the ore, or exploring the nature 
of its bed appeared to be very superficial. The earth falling 
in had filled up those excavations, and we could not jud<m 
ot the richness of the lobe. Notwithstanding the expense 
incurred under the intendancy of Don Jose Avalo, the 
great question whether the province of Venezuela contains 
mines rich enough to be worked, is yet problematical, 
though in countries where hands are wanting, the cul- 
ture of the soil demands unquestionably the first care of 
the government, yet the example of New Spain suffi- 
ciently proves that mining is not always unfavourable to 
the progress of agriculture. The best-cultivated Mexican 
