4 



] 66 On the Pitch Laie of the Island of Trinidad. 



world; but I have been informed bv several persons that 

 the sea in the neighbourhood of La Braye is occasionally 

 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 proba- 

 bility, that in all these cases the pilch was originally fluid, 

 and has since become inspissated by exposure to the air, as 

 hsppens in the Dead Sea and other parts of the East. 



It is for geologists to explain the origin of this singular 

 phaenonienon, and each sect will doubtless give a solution 

 of the difficulty according to its peculiar tenets. To frame 

 any very satisfactory hypothesis on the subject, would re- 

 quire a more exact investigation of the neighbouring coun- 

 try, and particularly to the southward and eastward, which 

 I had not an opportunity of visiting. And it must be re- 

 membered that geological inquiries are not conducted here 

 with thai facility which they are in some other parts of the, 

 world : the soil is almost universallycovered with the thickest 

 and most luxuriant vegetation, and the stranger is soon ex- 

 hausted and overcome by the scorching 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 na- 

 ture 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 ex- 

 perienced the efi'ects of the volcanic power, which, as he 

 supposes, elevated the grea' mountains on the main and the 

 northern side of the island*. The production of all bitu- 

 minous substances has certainly with plausibility been at- 

 tributed to the action of subterranean fires on beds of coal, 

 being separated in a similar manner as when eflfecled by 

 artificial heat, and thus they may be traced through the va- 

 rious transformations of vegetable matter. I was accord- 

 ingly particular in iny inquiries with regard to the existence 

 of beds of coal, but could not learn that there was any cer- 

 tain trace of that substance in the 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 



* Vide Philos. Trans, vol. hxix. or Ann. Register for 1789. 



of 



