& PERU. [CHAP. xVi. 



both inhabitants and foreigners suffer from severe attacks of ague. 

 This disease is common on the whole coast of Peru, but is unknown 

 in the interior. The attacks of illness which arise from miasma never 

 fail to appear most mysterious. So difficult is it to judge from the 

 aspect of a country, whether or not it is healthy, that if a person had 

 been told to choose within the tropics a situation appearing favourable 

 for health, very probably he would have named this coast. The plain 

 round the outskirts of Callao is sparingly covered with a coarse grass, 

 and in some parts there are a few stagnant, though very small, pools of 

 water. The miasma, in all probability, arises from these : for the town 

 of Arica was similarly circumstanced, and its healthiness was much 

 improved by the drainage of some little pools. 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 climate, 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 this period the air appears to become quite poisonous ; both natives 

 and foreigners often being affected with violent fevers. On the other 

 hand, the Galapagos Archipelago, in the Pacific, with a similar soil, 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 dangerous, being surrounded, as at Vera 

 Cruz and Carthagena, with an arid and sandy soil, which raises the 

 temperature of the ambient ah-."* On the coast of Peru, however, the 

 temperature is not hot to any excessive degree ; and perhaps in conse- 

 quence, the intermittent fevers are not of the most malignant order. Ir 

 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 greatei 

 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 

 the other hand, I have heard of one remarkable case where a fever 

 broke out among the crew of a man-of-war some hundred miles off the 

 coast of Africa, and at the very same time that one of those fearful 

 periods f of death commenced at Sierra Leone. 



No State in South America, since the declaration of independence, 

 has suffered more from anarchy than Peru. At the time of our 



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



f A similar interesting case is recorded in the Madras Medical Quarterly 

 Journal, 1839, p. 340. Dr. Ferguson, in his admirable Paper (see 9th vol. of 

 Edinburgh Royal Transactions}, shows clearly that the poison is generated in 

 the drying process; and hence that dry hot countries are often the most 

 unhealthy, 



