104 Dr. Mac CiiUoch's Essay on the 



It is shown, and by facts, that the rushy swamps of high 

 moorlands, however small the extent, do produce this dis- 

 ease ; and we must not here forget to name what, however, 

 belongs to the preceding chapter, woods and coppices, little 

 suspected in England, yet shown to be the cause of fevers in 

 Wales, and also in Sussex; very probably, every where else. 

 It is also shown that meadows and moist pastures, whether 

 in flat lands or on elevations, generate fevers ; and very par- 

 ticularly, should they have been affected by inundation or 

 unusual moisture, and if that should be followed by heat. 

 And while it is also specifically shown how, in all cases, it is 

 the produce of the drains or ditches required in meadow 

 lands, it is distinctly proved that, even without these, ma- 

 laria is produced, or that it is generated by the meadow or 

 moist pasture itself. 



It is also shown that this poison is produced by rivers, by 

 all flat rivers at least, or those of which the progress is slow 

 and through meadow lands ; while this is pointed out as one 

 of the causes, especially, which is not suspected or not be- 

 lieved in England. And here we can add a fact to our 

 author's statement, which is decisive : this is the case of the 

 barracks at Morne Bruce, in Dominica, situated on a steep 

 and rocky hill, perfectly dry, and free from all other causes 

 of suspicion, while eternally subject to the most severe fevers. 

 And the cause is, a mountain stream, about 300 yards be- 

 low this building, in the valley, always covered by a mist 

 in the evenings, and ascertained, by direct experience, to be 

 the very cause of the diseases in question. 



Our author also notices canals, mill-ponds, ornamental 

 waters, and all other pools and ponds, even to so small a 

 dimension as those formed in gravel-pits; pointing out those, 

 in particular, as common causes of fever about London, and 

 apparently much inclined to pass a very severe judgment on 

 the canal in St. James's Park, and also on the pond in St. 

 James's Square, while apparently restrained by his pruden- 

 tial reasons, which appear to us sufficiently misplaced, or, as 

 we should fairly call them, somewhat absurd. But as we 

 must not affront a writer whose papers we have admitted, 

 we shall say no more on this matter. In noticing drains, he 

 also speaks of moats and modern fortifications ; attempting 

 to show that the fevers so common in the sieges of ancient 

 castles were produced by their moats, and noticing the fami- 

 liar fact of the frequency of fevers in fortified towns. Lakes 

 also are pointed out as situations generating this poison : and 

 it is here especially noticed that if, in those and other cases, 

 malaria is produced by the vegetable growth and decompo- 



