On Malaria. 325 



marsh, is of equal efficacy, by opening a channel for a free current 

 of land winds to carry off the exhalations. I scarcely need add, 

 that when irreclaimable marshes are on the sea shore, at the outlet of 

 narrow valleys, groves on the landward side should be planted, to 

 prevent sea winds from passing over them into the interior. 



Fires and smoke have been found of great utility, especially in mil- 

 itary service, as was proved on a large scale, by Buonaparte, before 

 Mantua ; and in Africa, the experiment in a small way, has proved 

 successful. Emigrants proceeding to Alabama and other southern 

 regions, from the low countries of Carolina, find no injury from sleep- 

 ing in the open air, as their custom at night is to build a large fire of 

 logs, and lay themselves beside it, on some part of their baggage. 

 The effect of fires in destroying malaria, is plain, if the fact of its ex- 

 istence depends upon the presence of moisture ; for the moisture be- 

 ing evaporated by the heat, the poison is either dispersed with the va- 

 por, or if separated from it, falls innoxious, and probably inert. It is on 

 the same principle, that smoking segars on the decks of ships is salu- 

 tary. The heat and smoke, keep a dry atmosphere about the un- 

 covered face, and the air respired, being thus deprived of mias- 

 mata, is safe. This view of the subject suggests another ground 

 of suspicion, that the poison acts upon the surface ; which is support- 

 ed by the fact, that a strong malarious breeze, often strikes seamen 

 arriving on such coasts with instant cholera, apoplexy, and other sud- 

 denly fatal diseases, and this from the sympathy of the stomach with 

 the skin, and of the brain with the stomach. I offer this as conjec- 

 ture merely ; but I may add in favor of the hypothesis, that it is dur- 

 ing sleep in the open air, when the pores of the skin are peculiarly 

 relaxed and sensitive, that the poison operates with the most fatal ac- 

 tivity and certainty. 



It is necessary for people in exposed situations, either from the vi- 

 cinity of pestilential places, or the prevalence of endemic sickness, 

 to beware of causes, which may render them obnoxious to its 

 effects ; and a due attention to the following suggestions will not 

 be without use. Regular and sufficient sleep : exercise without fa- 

 tigue : substantial food, equally removed from a low abstemious diet, 

 or a luxurious stimulating aliment : moderately warm clothing : scru- 

 pulously avoiding the evening air : and as far as possible a quiet 

 mind. To these may be added, fires lighted for an hour or two, 

 morning and evening, in every apartment of a house; and ifpractica- 



