1M>U.J WALE — VENEZUELA iKD TREJIDAD, 481 



diiied or rejected in accordance with the advance of science during 

 tin' last sixty years, yet many of the results at which In- arrived 

 form a permanent addition to our knowledge, ami will be verified by 



each of his followers. 



A quarter of a century later, the Frcmh chemist Boussingault 

 visited the same territory, and executed a number of researches, less 

 general, but more detailed, and relating especially to the composition 

 of the thermal waters and the distribution of the natural asphaltum. 



The yeai- 1841 witnessed the publication of the labours of Colonel 

 Codazzi on the physical geography of Venezuela*, including a Beries 

 of maps prepared from the topographical surveys and measurements 

 conducted by him during more than ten years. This is an especially 

 important work for the geological inquirer, furnishing him with 

 m my of the data so essential to the accuracy of his observations. 

 It Lb not only the execution of these maps, though numerous and 

 faithful, hut also the precision with which the external features, 

 the resources, and capabilities of the various regions are determined, 

 that confers so high a value on this summary.— a value only to bo 

 duly appreciated by those who have traversed the country, and can 

 realize the difficulties attending the performance of such labours, 

 which, at the date of their publication, were quite exceptional, no 

 similar compendium then existing for any other South American 

 province. 



Although that continent, possessing a magnificent system of rivers, 

 and colossal mountain-chains, and a vegetation of the most varied 

 and interesting description, presents unsurpassed attractions to tho 

 scientific explorer, yet it is to be apprehended thai many years must 

 elapse before our knowledge will partake of that precise and posi- 

 tive nature which already attaches to the investigations conducted in 

 Beveral much more recently settled countries. The constant political 

 disturbances which agitate the South American Republics keep the 



various States in such an impoverished condition as to render their 

 governments unable to support any regular scientific organization. 

 Cinder these circumstances, we may Long be dependent for the exten* 

 Hun of our Lnformation respecting these regions on the mere casual 

 visitor or resident, who, having but Limited resources in a field bo 

 vast, finds him -eit reduced to contend with difficulties frequently 

 beyond the power of individual effort to control or overcome. 



North of the Orinoco, tie' principal inequality in the surfs I 



Venezuela consists of a massive and elevated mountain-range known 



as the Littoral Cordillera. 



To ascertain the origin of this striking physical feature, it is 

 accessary to refer to the main chain of the Amies, which, a little 

 north of the frontiers of Ecuador ami New Granada, divides into 

 three greal ran - , XXI.). I »f these, the w i stern folio* - the 



oontour of the ooast towards Panama*; the central continuing to the 

 north in the direction of Carthagena; whilst the eastern, assuming 



a north-eastern OOUTSe after passim :id originating B pOWOT- 



• i Wiuziula: Paris, 1841. 



