CATARACTS, AND INUNDATIONS. 



daily deposited by the gulf, and with the composition of the porce 

 lain jasper in immediate contact with the bituminous mass. 



All the country which I have visited in Trinidad is either decidedly 

 primitive or alluvial. The great northern range of mountains which 

 runs from east to west, and is connected with the Highlands of Paria 

 on the continent by the Islands at the Bocas, consists of gneiss, of 

 mica slate containing great masses of quartz, and in 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, with frequent veins of white crystallized carbonate of 

 lime. From the foot of these mountains, for many leagues to the 

 southward, there is little else than a thick fertile argillaceous soil, 

 without a stone or a single pebble. This tract of land, which i* 

 low and perfectly level, is evidently formed by the detritus of the 

 mountains, and by the copious tribute of the waters of the Oroonoco, 

 which being deposited by the influence of currents, gradually accu- 

 mulates ; and in a climate where vegetation is astonishingly rapid, 

 is speedily covered with the mangrove and other woods. It is- 

 accordingly observed, that the leeward side of the island constantly 

 encroaches on the gulf, and marine shells are frequently found on 

 the land at a considerable distance from the sea. This is the 

 character of Naparima and the greater part of the country I saw 

 along the coast to la Braye. It is not only in forming and extending 

 the coast of Trinidad, that the Oroonoco exerts its powerful agency: 

 co-operating with its mighty sister flood, the Amazons, it has mani- 

 festly formed all that line of coast and vast extent of country 

 included between the extreme branches of each river. To use the 

 language of a writer in the Philosophical Transactions of Edinburgh ; 

 " If you cast your eye upon the map, you will observe from Cayenne 

 to the bottom of the Gulf of Paria this immense tract of swamp, 

 formed by the sediment of these rivers, and a similar tract of 

 hallow muddy coast, which their continued operation will one day 

 elevate. The sediment of the Amazons is carried down thus to 

 leeward (the westward) by the constant currents which set along 

 from the southward and the coast of Brazil. That of the Oroonoco 

 is detained and allowed to settle near its mouths by the opposite 

 island of Trinidad, and still more by the mountains on the main, 

 which are only separated from that island by the Bocas del Drago. 

 The coast of Guiana has remained, as it were, the great eddy or 



