THE CINCHONA TREE. 
211 
place by the passage of Fomalhaut over the meridian; but 
the observation was lost, owing to the time I employed 
in taking the level of the artificial horizon. It was midnight, 
and I was benumbed with cold, as were also our guides : yet 
the thermometer kept at 197°. At Cumana 1 have never 
seen it sink below 21°; but then the house in wliich we 
(.welt on the Imposiblc was 258 toises above the level of 
'.he sea. At the Casa de la Polvora I determined the dip of 
the magnetic needle, which was 42‘5°. # The number of. 
oscillations correspondent to 10' of time was 233. The in- 
tensity of the magnetic forces had consequently augmented 
from the coast to the mountain, perhaps from the influence 
of some ferruginous matter, hidden in the strata of sand- 
stone which cover the Alpine limestone. 
We left the Imposible on the 5th of September before 
sunrise. The descent is very dangerous for beasts of burden; 
the path being in general but fifteen inches broad, and 
bordered by precipices. In descending the mountain, we 
observed the rock of Alpine limestone reappearing under the 
sandstone. The strata being generally inclined to the south 
and south-east, a great number of springs gush out on the 
southern side of the mountain. In the rainy season of the 
year, these springs form torrents, which descend in cascades, 
shaded by the hura, the cuspa, and the silver-leaved cecropia 
or trumpet-tree. 
The c-uspa, a very common tree in the environs of Cumana 
and of Bordones, is yet unknown to the botanists of Europe. 
It was long used only for the building of houses, and has 
become celebrated since 1797, under the name of the casea- 
rilla or bark- tree (cinchona) of New Andalusia. Its trunk 
rises scarcely above fifteen or twenty feet. Its alternate 
leaves are smooth, entire, and oval.+ Its bark very thin, and 
of a pale yellow, is a powerful febrifuge. It is oven more 
bitter than the bark of the real cinchona, but is less disa- 
greeable. The cuspa is administered with the greatest suc- 
cess, in a spirituous tincture, and in aqueous infusion, both 
in intermittent and in malignant fevers. 
* The magnetic dip is always measured in this work, according to thr 
seutebimal division, if the contrary be not expressly mentioned. 
t At the summit of the boughs, the leaves are sometimes opposite lu 
osch other, but invariably without stipules. 
p 2 
