52 



The extreme slowness, with which the tem- 

 perature increases during the passage from Spain 

 to the New Continent, is highly advantageous to 

 the health of Europeans, who go to settle in the 

 colonies. At Vera Cruz and at Carthagena, the 

 Creoles who descend from the high savannahs of 

 Bogota, and the central elevated plain of New 

 Spain, are more exposed on the coasts to the 

 attack of the yellow fever, or vomito, than the in- 

 habitants of the north, who arrive by sea*. In 

 travelling from Perote to Vera Cruz, the Mexi- 

 cans descend in sixteen hours from the region 

 of pines and oaks, from a mountainous country 

 where the thermometer very often sinks at noon 

 to four or five degrees, to a burning plain co- 

 vered with cocoa trees, with mimosa cornigera, 

 and other plants that vegetate only under the 

 influence of a strong heat. These mountaineers 

 feel a difference of temperature of eighteen de- 

 grees; and this difference produces the most 

 fatal effects on the organs, by exciting their irri- 

 tability. The European, on the contrary, crosses 

 the Atlantic Ocean in thirty-five or forty days ; 

 he prepares himself gradually for the sweltering 

 heats of Vera Cruz, which, without being the 

 direct cause of the yellow fever, do not the less 

 contribute to the rapidity of it's progress. 



A very sensible decrement of heat is observed 



* Nouv. Esp. t. ii, p. 772. 



