BtILl>llL'KJirT£D SPBISGS. 
103 
^ade an excursion thither on a cool and misty morning. 
. he Waters, which are loaded with sulphuretted hydrogen, 
'ssue from a quartzose sandstone, lying on compact lime- 
atone,the same as that we had examined at the Morro. Wo 
again found in this limestone intercalated beds of blach 
^ornstein, passing into kieselschiefer. It is not, however, 
transition rock; by its position, its division into small 
*'ata, its wliiteness, and its dull and conchoidal fractures, 
v'lth very flattenned cavities), it rather approximates to the 
'hiestone of Jura. The real kieselschiefer and Lydian- 
have not been observed hitherto except in the transl- 
'on-slatcs and limestones. Is the sandstone, whence the 
Priiigg of the Bergantin issue, of the same formation as 
he sandstone of the Impossible and the Tumiriquiri ? The 
hiiiperature of the thermal waters is only cent, (the 
'^P®psphero being 27°). They flow first to the distance 
lorty toises over the rocky surface of the ground ; then 
_}^y rush down into a natural c.avem; and finally they 
J through the limestone, to issue out at the foot of the 
jOuntain, on the left bank of the little river Narigual. 
springs, while in contact with the oxygen of the 
u^®pbere, deposit a good deal of sulphur. I did not col- 
iu ■ ^ done at Mari.ara, the bubbles of air that rise 
from these thermal waters. They no doubt cou- 
hvH quantity of nitrogen ; because the sulphuretted 
°g6ii decomposes the mixture of oxygen and nitrogen 
j olved in the spring. The sulphurous waters of Sun 
which issue from calcareous rock, like those of the 
have also a low temperature, (:il'3°) ; wliilo in 
of region, the temperature of tlic suljfliurous waters 
lariara and Las Truichcras (near Porto Cabello), which 
^®'nediately from gneiss-granite, is 58'9® the former, 
the latter. It would seem as if tlie heat which 
jjj springs acquire in the interior of the globe, dimiuishes 
as they pass from primitive to secondary 
®adeT to tlio Aguas Calientes of Bergautin 
of h' ^ vexatious accident. Our host had lent us one 
time** tinest saddle-horses. We were warned at the same 
oypj. ®°t to ford the little river of Narigual. We passed 
*<• sort of bridge, or rather some trunks of trees laid 
