July, 1835. LIMA. 447 



for the town of Arica was similarly circumstanced, and its 

 healthiness was much improved by the drainage of the 

 water. The miasma is not always produced by a luxuriant 

 vegetation with an ardent climate ; for many parts of Brazil, 

 even where there are marshes and a rank vegetation, are 

 much more healthy than this sterile coast of Peru. The 

 densest forests in a temperate chmate, as in Chiloe, do not 

 seem in the slightest degree to affect the healthy condition 

 of the atmosphere. 



The island of St. Jago, at the Cape de Verds, offers 

 another strongly-marked instance of a country which any 

 one would have expected to find most healthy, being very 

 much the contrary. I have described the bare and open 

 plains as supporting, during a few weeks after the rainy 

 season, a thin vegetation, which directly withers away 

 and dries up : at that period the air appears to become 

 poisonous; both natives and foreigners often becoming 

 affected with violent fevers. On the other hand, the 

 Galapagos Archipelago, in the Pacific, with a similar sod, 

 and periodically subject to the same process of vegetation, 

 is perfectly healthy. Humboldt has observed, that, " under 

 the torrid zone, the smallest marshes are the most dan- 

 gerous, being surrounded, as at Vera Cruz and Cartha- 

 gena, with an arid and sandy soil, which raises the tem- 

 perature of the ambient air.^'* I must observe, however, 

 that on the coast of Peru the temperature is not hot to any 

 excessive degree; and perhaps in consequence, the inter- 

 mittent fevers are not of the most malignant order. 



In all unhealthy countries the greatest risk is run by 

 sleeping on shore. Is this owing to the state of the body 

 during sleep, or to a greater abundance of miasma at such 

 times ? It appears certain that those who stay on board a 

 vessel, though anchored at only a short distance from the 

 coast, generally suffer less than those actually on shore. On 



* Political Essay on the Kingdom of New Spain, vol. iv., p. 199. 



