393 



from eight to ten feet in depth. It was sup- 

 posed that they had issued from some subter- 

 raneous basin, formed by successive infiltra- 

 tions into the recently cleared arable lands. 

 Many houses were carried away by the tor- 

 rent ; and the inundation became more dan 

 gerous for the stores, in consequence of the gate 

 of the town, which could alone have given an 

 issue to the waters, being accidentally shut. 

 It was necessary to make a breach in the wall on 

 the seaside ; more than thirty persons perished, 

 and the damage was computed at half a million 

 of piastres. The stagnant waters, which infect- 

 ed the stores, the cellars, and the dungeons of 

 the public prison, no doubt diffused miasmata in 

 the air, which, as predisposing causes, may 

 have accelerated the developement of the yel- 

 low fever; but I believe that the inundation 

 of the Rio de la Guayra was as little the pri- 

 mary cause, as the overflowings of the Guadal- 

 quiver, the Xenil, and Gual- Medina, were at 

 Seville, at Ecija, or at Malaga, in the fatal epi- 

 demics of 1800 and 1804. I examined with 

 attention the bed of the torrent of La Guayra ; 

 and saw there only a barren soil, blocks of 

 mica-slate and gneiss, containing pyrites, and 

 broken off from the Sierra de Avila, but nothing 

 that could have had any effect on the purity of 

 the air. 



Since the years 1797 and 1798, the same in 



