On Malaria, 45 



effect of the sea breeze, by crossing such marshy ground, to 

 convey the malaria up into the interior country, to considerable 

 distances, and to places which are in themselves not insalu- 

 brious. Thus, also, does such a breeze, especially when it is a 

 warm wind, convey the poison up the acclivities of hills, even 

 to a considerable range of distance or elevation; a process 

 facilitated by the natural tendency of such winds to ascend. 

 And as a striking proof of this migration of malaria, it appears 

 from Capt. Smyth's statistical account of the insalubrious vil- 

 lages in Sicily, that out of more than seventy, about one-half 

 are not seated near or on lands producing this substance, but 

 on acclivities, at varying distances — thus receiving it through 

 migration. The same is remarked by Montfalcon of many 

 towns in France ; while in some, the place at a distance is even 

 more unhealthy than that which is immediately situated in the 

 marsh itself: and in our own country, this is equally said to be 

 true of the backwater at Weymouth, and of the marshes of St. 

 Blasey in Cornwall, acting more powerfully at some distance 

 than in the immediate spot. 



With respect to the absolute distance to which the malaria 

 can be conveyed, it is yet an obscure circumstance, or at least 

 the maximum has not been fixed ; but it is at least ascertained 

 that the convent of Camaldoli receives it from the Lake 

 Agnano, at a distance of three miles; while from certain 

 naval reports, a distance of five miles has been proved to 

 permit its transmission, — and from an evidence that cannot be 

 doubted, inasmuch as it was the sudden breaking out of fever 

 in a healthy ship, anchored at that distance from the shore, on 

 the coming off of the land wind, attended by its peculiar and 

 well-known smell. 



These facts are satisfactory thus far, and it would be abund- 

 antly easy to add to them; but there is reason to suspect that 

 it can be conveyed to far greater distances, in certain favour- 

 able circumstances: those reasons, in the first place, being 

 derived from certain meteorological analogies and considera- 

 tions, and in the next confirmed by experience. It is notorious 

 that the ague appears on our eastern coasts with the first east 

 winds of spring ; and while this circumstance is most common 

 on those of England, as for example, in Kent, Essex, Norfolk, 



