Proceedings of Learned Societies, 
47S 
ISil.] 
It is observed by Capt. Mallet, in his 
Short Topographical Sketch of the island, 
that near Cape la Brea (la Braye) a 
little to the south-west, is a gulf or vor¬ 
tex, which in stormy weather gushes-out, 
raising the w'ater five or six feet, and 
covers the surface for a considerable 
space with petroleum or tarand he 
adds, that “ on the east coast in the Bay 
of Mayaro, there is another gulf or vor¬ 
tex similar' to the former, which in the 
months of March and June produces a 
detonation like thunder, having some 
flame with a thick black smoke, which 
Vanishes away immediately: in about twen¬ 
ty-four hours afterwards is found along 
the shore of the bay a quantity of bitu¬ 
men or pitch, about three or four inches 
thick, which is employed with success.” 
Captain Mallet likewise quotes Gumilla, 
as stating, in his Description of Orinoco, 
that, about seventy years ago a spot of 
land on the western coast of this island, 
near half way between the capital, an In¬ 
dian village sank suddenly, and was im¬ 
mediately replaced by a small lake of 
pitch, to the great terror of the inhabi¬ 
tants.” 
I have no opportunity of ascertaining 
personally whether these statements are 
accurate, though, sufficiently probable 
from what is known to occur in other 
parts of the w'oild ; but I have been in¬ 
formed by several persons that the sea in 
the neighbourhood of La Braye is occa¬ 
sionally covered with a fluid bitumen, 
and in the south-eastern part of the island 
there is certainly a similar collection of 
this bitumen, though of less extent, and 
many small detached spots of it are to be 
met with in the woods; it is even said 
that an evident line of communication 
may thus be traced between the two great 
receptacles. There is every probability, 
that in all these cases the pitch was ori¬ 
ginally fluid, and has since become in¬ 
spissated by exposure to thq air, as hap¬ 
pens in the Dead Sea and other parts of 
the East. 
It is for geologists to explain the origin 
of this singular phasnomeiion, and each 
iSect will doubtless give a solution of the 
difficulty according to its peculiar tenets. 
To frame any very satisfactory hypothe¬ 
sis on the subject, would require a more 
exact investigation of the neighbouring 
country, and particularly to the south¬ 
ward and eastward, which I had not an 
opportunity of visiting. And it must be 
remembered that geological inquiries are 
not conducted here with that facility 
which they are in some other parts of 
Me.\% Mao,, De«, 1 / 1811 , 
world .* the soil is almost universally co* 
vered with the thickest and most luxuri¬ 
ant vegetation, and the stranger is soon 
exhausted and overcome by the scorc/i-* 
ing rays of a vertical sun. Immediately 
to the southward, the face of the country, 
as seen from La Braye, is a good deal 
broken and rugged, which Mr. Anderson 
attributes to some convulsion of nature 
from subterranean fires, in which idea 
he is confirmed by having found in the 
neighbouring woods several hot springs. 
He is indeed of opinion that this tract 
has experienced the effects of ti^e vol¬ 
canic power, which, as he supposes, ele¬ 
vated the great mountains on the main 
and the northern side of the island.* 
The production of all bituminous sub¬ 
stances has certainly with plausibility 
been attributed to the action of subter¬ 
ranean fires on beds of coal, being sepa¬ 
rated in a similar manner as when effect¬ 
ed by artificial heat, and thus they may 
be traced through the various transfor¬ 
mations of vegetable matter. I was ac¬ 
cordingly particular in my enquiries with 
regard to the existence of beds of coal,, 
but could not learn that there was any 
certain trace of that substance in tiie 
island ;and, though it may exist at a great 
depth, I saw no strata that indicate it, 
A friend, indeed, gave me specimens of 
a kind of bituminous shale mixed with 
sand, which he brought from Point Cedar, 
about twenty miles distant, and I find 
Mr. Anderson speaks of the soil near the 
pitch lake containing burnt cinders; but 
I imagine he may have taken for them 
the small fragments of the bitumen it¬ 
self. 
All the country which I have visited 
in Trinidad is either decidedly primitive 
or alluvial. The greaf northern range of 
mountains which runs from east to west, 
and is connected with the islands of Paiia 
on the continent by the Islands at the 
Bocas, consists of gneiss, of mica slate 
containing great masses of quartz, and ia 
many places approaching so much to the 
nature of talc as to render the soil quite 
unctuous by its decomposition, and of 
compact blueish gray limestone, v.-ith 
frequent veins of white crystallised car¬ 
bonate of lime. From the foot of these 
mountains, for many leagues to th;^ south¬ 
ward, there is little else than a thick fer¬ 
tile argillaceous soil, without a stone or a 
single pebble. This tract of land, w hich 
is low and perfectly level, is evidently 
formed by the detritus of the mountains, 
* Vide Philos. Trans, voi. Ixxix. or y-vna. 
Register for 1789* 
i P anil 
