210 
MEXICO. 
attained the limit of vegetation, when they saw but a few pines — whose 
gnarled and twisted branches exhibited scarcely a sign of verdure. Some 
small singing birds flew by them, and the plants they had observed in 
the course of their ascent thus far, are mentioned in the subjoined note.* 
At this spot our travellers found a wide desert of black volcanic sand, 
covered with fragments of pumice. They were soon warned of approach- 
ing difficulties. The clouds gathered in thick masses around the top of 
the volcano portending a storm ; and, scarcely had they retreated again 
to their tent, when it came down on them with all the mercilessness of a 
tropical hurricane. For several hours during the ensuing night the sur- 
rounding wastes were lit up with incessant flashes of the most brilliant 
lightning, shooting from the clouds above and lelow them, and at times 
even streaming horizontally along the wastes of dreary sand, crashing the 
branches of the forest and rending the stoutest pines. They seemed, en- 
veloped in flame — yet they had no protection from the fury of this storm 
of hail and thunder but a scanty cloth, thrown over the limb of a tree and 
pegged to the ground ! 
Thus passed the night until four o'clock. When day dawned, they 
found the mountain covered with snow, and the summit entirely enveloped 
in clouds. Nevertheless they resolved to proceed, and, with the greatest 
difficulty, prevailed on the Indians to accompany them. 
For a league and a half farther, they advanced on horseback, but the 
pathway became so deep and yielding in the sand, that they were forced 
to dismiss their servants with the animals, and continue with the guides 
alone. The toil of ascending on foot now commenced, and they describe 
it. as one of the most agonizing they ever underwent; sliding back half 
the distance they had made in advance at every footstep, and laboring 
with the increased circulation to such a degree that they could scarcely 
breathe. Yet they persevered resolutely for several hours, until the ill- 
shod Indians, whose feet were cut by the snow and sands, gave out en- 
tirely, and the Baron and Mr. Von Gerolt were forced to proceed wholly 
unattended. It was about this time that the sun broke out from the clouds, 
for which (although they disregarded it then,) they paid dearly enough 
in the sequel. 
At noon, after immense fatigue and exertions, they found themselves at 
• Salvia, three species. 
Ijobelia, three species. 
Baccharis. Cineraria, four 
species. 
Stevia. do. do. 
Acacia. 
Jjeonia-salvifolia, do. do. 
Oestrum, two species. 
CEnotera, do. do. 
Asclepias, do. do. 
t'uctisia. 
Iresine, do. do. 
Achyrophorus roseus. 
Arbutus, do. do. 
Those nearest the limit of vegetation wei»i 
Gupatorium, do. do. 
Chelone, gentianoides. 
Hedyotis, three 
species. 
Amaryllis, minuta. 
Viburnum, do. 
do. 
Phffilia. 
Coroepsia, do. 
do. 
Costilleja. 
Myosotis erandifiora, do. 
do. 
Lupinus-vaginatui. 
do flor. alb. do. 
do. 
Ribes, odoratum. 
Stacbys, do. 
do. 
Aienaria biyoidet 
