PREVALENCE OF THE PLAQUE OF MOSQUITOS. 279 



region, where the mean heat is below 19* or 20 ; and that, 

 with few exceptions, they shun the black waters, and dry 

 and unwooded spots.* The atmosphere svrarms with them 

 much more in the Upper than in the Lower Orinoco, 

 because in the former the river is surrounded with thick 

 forests on its banks, and the skirts of the forests are not 

 separated from the river by a barren and extensive beach. 

 The mosquitos diminish on the New Continent with the 

 diminution of the water, and the destruction of the woods ; 

 but the effects of these changes are as slow as the progress 

 of cultivation. The towns of Angostura, Nueva Barcelona, 

 and Mompox, where from the want of police, the streets, the 

 great squares, and the interior of court-yards are overgrown 

 with brushwood, are sadly celebrated for the abundance of 

 zancudos. 



People born in the country, whether whites, mulattoes, 

 negroes, or Indians, all suffer from the sting of these insects. 

 But as cold does not render the north of Europe uninha- 

 bitable, BO the mosquitos do not prevent men from dwelling 

 in the countries where they abound, provided that, by their 

 situation and government, they afford resources for agricul- 

 ture and industry. The inhabitants pass their lives in com- 

 plaining of the insufferable torment of the mosquitos, yet, 

 notwithstanding these continual complaints, they seek, and 

 even with a sort of predilection, the commercial towns of 

 Mompox, Santa Marta, and Rio de la Hacha. Such is the 

 force of habit in evils which we suffer every hour of the day, 

 that the three missions of San Borja, Atures, and Esmeralda, 

 where, to make use of an hyperbolical expression of the 

 monks, "there are more mosquitos than air,"* \vould no 

 doubt become nourishing towns, if the Orinoco afforded 

 planters the same advantages for the exchange of produce, 

 as the Ohio and the Lower Mississippi. 



It is a curious fact, that the whites born in the torrid 

 zone may walk barefoot with impunity, in the same apart- 



* Trifling modifications in the waters, or in the air, often appear to 

 prevent the development of the mosquitos. Mr. Bowdich remarks that 

 there are none at Coomassie, in the kingdom of the Ashantees, though the 

 town is surrounded by marshes, and though the thermometer keeps up 

 between seventeen and twenty-eight centesimal degrees, day and night. 

 t Mas moscas que aire. 



