148 THE GREAT CAT AE ACTS OF THE OEINOCO. 



the mission of San Borja, the suffering from mosquitoes is 

 greater than at Caricliana ; but in the Raudales, at Atures, 

 and, above all, at Maypures, this suffering may be said to 

 attain its maximum. I doubt whether there be a country 

 upon earth where man is exposed to more ci-uol torments 

 in the rainy season." 



On oxir second evening at the village of Atures, we 

 Avalked to the river to see how our boat advanced up the 

 cataracts. Nine men had been employed in the Avork, and 

 had succeeded in bringing it through the rapids to where 

 it became necessary to drag it some distance overland, 

 by putting it upon rollers, as at this point obstructions 

 completely filled the eastern channel of the river — the one 

 we were ascending. The rocks exhibited those peculiar 

 erosions, called " pot-holes," twenty or more feet in depth, 

 and from three to five feet in diameter ; while at their 

 bottom were small stones and quartz-gravel, which, given 

 a revolving motion by the action of the water, had slowly 

 drilled themselves tlirough the solid rock. The primitive 

 rock of the Great Cataracts is a coarse-grained granite, 

 often containing hornblende ; yet it does not constitute 

 true syenite. We observed traces of black coating upon 

 the stones wherever they are washed by the water, such 

 as excited the interest of Humboldt ; yet they did not 

 exhibit that glistening, metallic appearance which that 

 traveller mentions as giving such a singular aspect to this 

 wild river-scenery. 



North of the village of Atures, and nearly two leagues 

 distant, is a settlement of a few houses, called Pueblo 

 Viejo, the old town, which, like the one upon the line of 

 portage, was at one time quite a flourishing village ; but 

 the plague of insects, with the insalubrity of the climate in 

 these misty and heated districts, caused its depopulation, 

 and it has fallen nearly into decay. It is surprising that 

 any persons should so persistently remain ; but the attach- 



