On the Natural Hi/lory of Guiana. 35 1 



the main body of the low land of Guiana is laid down as favannah ; and the woody coun- 

 try, which a ftranger or fuperficial obferver would fuppofe to be the whole, or much the 

 greater part of it, is in fad only a border on the fides of the rivers and of the fea, but of 

 confidcrable breadth, more or lefs iii proportion to the fize of the adjoining river, or, 

 which is generally the fame thing, to the acquired height and extent of the foil on either 

 bank. It fellowed as a confcquence, and as far as we had opportunities of obferving' 

 found it to be the cafe, ihat the low land was fomewhat higher, and continued fo 

 farther down about the Eflequebo, than the Demerary ; the woods, confequently, were of 

 greater extent. We found, befides, in the foil adjoining the Eflequebo, at leaft upon the 

 caft fide, a mixture of fand. The river is full of fand-banks ; and it appears, that the 

 finer parts of even this lefs fufpenfible fubftance are raifed by the floods, and carried 

 among the adjacent woods, to be depofited with the mud. The Mahayka, a fmall river 

 or creek, which falls into the fea about twenty or thirty miles to the eaftward of the De- 

 merary, though it runs a long way up the country, and fpreads into many branches, has 

 but a very narrow and often interrupted border of wood upon its banks ; it runs through 

 an immenfe favannah, and fo do its branches, with little or no wood till they approach 

 the fand-hills. The Deltas of the river of Oronooko, and its numerous mouths, make a 

 figure even in the map of the world. It is to be regretted that itsnoble flream has been 

 fo long hid from fcience. What I learned in Trinidad, from a gentleman who had failed 

 from its mouth to the Angufturas, about 300 miles up, confirms and illuftrates, in the 

 fulled manner, the above general rule. The weftern mouths of it, oppofite Trinidad, 

 are navigable only for launches drawing fix or feven feet water. At and oppofite them 

 the bottom is fliallow and muddy, and the coaft a low mangrove fwamp, refembiing in all 

 refpefls that of Guiana. You mud afcend thofe branches feveral days before you reach 

 the main dream ; and in doing fo you find the fame phenomena as in afcending the De- 

 merary, but in a dill greater degree. At fird you have the mangrove, or fome fimilar 

 fwamp, and behind it, on both fides, for about twenty leagues, the land, if you can call 

 it fo, hardly emerging from the water. Afterwards the ground appears ; and, as you go 

 up, rifes dill higher and higher on the banks above the common level of the dream. The 

 trees become in the fame manner of different fpecies, and much taller than they were below. 

 The channel in which you are, from being wide grows narrower by degrees. It is from 

 about one and a half to three- fourths of a mile broad near the entrance, and when it joins 

 the main dream is not more than about 200 yards. It has then acquired a confidcrable 

 depth, and the banks may be about 20 feet high. Along the main dream of the river, 

 or Boca de Nafios, the gradual rife, and other circumdances attending it, are quite fimilar. 

 All this height of the bank, I can make no doubt, is entirely acquired ground, formed 

 by the fediment of the floods, greater near the dreams than at a didance from them ; 

 and though I have no knowledge of the nature of the land in the Deltas and their vici- 

 nity, 1 would not hefitate to fay, that great part of the interior body of each iiland, and 

 mod probably of the main, on either fide where it is low country, confids of nothing 

 clfe than wet favannnahs. 



Floods. — Before we leave the rivers, It may be proper to take notice of their floods. In 

 no indance of a large river does the univerfal law within the tropics fail, that they an- 

 nually overflow their banks for a certain feafon. What was a prodigy in the Nile during 



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