On Malaria. 
65 
which, it must be observed, may often produce disease, where the soil which they 
intersect may be incapable of that. In Italy, in France, in Spain, and in Greece, 
and almost invariably in the American states, they are not only causes of malaria, 
hut among the most common ones. The great seats of that poison in those coun- 
tries, are the vallevs and plains which give passage, to rivers, whether on entering 
the sea or otherwise ; and out of these, there is a very small proportion marshy, 
compared to those which are merely meadow and pasture, and which, very often al- 
so, are the seats of cultivation. Did meadow lands not produce malaria, there 
could be few of those tracts abandoned in summer, compared to those which it is 
nearly impossible to inhabit after the heats are once established, while, to refer to 
individual places, would be to form a catalogue of no small length. 
With respect to our own country, whoever shall please to inquire, will find 
that fevers occur in autumn, in those situations, particularly in hot seasons, when 
tfcev are unknown in the drier lands, and more especially in the cultivated ones ; 
nor can there be anv reason to doubt that it should he so, when our climate has 
been proved capable, like the southern countries of Europe, of producing this poi- 
son from the same class of soils. And whoever also will inquire, will often find great 
surprise expressed hy country practitioners, at the occurreuce of fevers in rural and 
detached situations, where the commonly esteemed cause, contagion, cannot be 
suspected ; while he who may pursue his inquiries on this principle, will be able to 
explain the causes without difficulty, from the presence of some spot or tract of this 
nature. And I must add, that it is not even necessary that such pasture-lands 
should he flat meadows, as I could easily produce instances of endemic fevers, al- 
most amounting to epidemics in the last summer, where the lands, being wet and 
poachy however, were not only elevated, butformed the declivities ofhills. 
There is one case of land, which, as to ourselves, is not worth noticing, as it 
does not occur among us — I mean rice-fields ; and if I here enumerate them, it is 
for the sake of preserving the integrity of the subject. But it gives me an oppor- 
tunity of introducing one or two remarks which do concern us : the most impor- 
tant of which is, that meadow-lands will be pernicious in summer, in proportion 
as they have been wet the preceding winter, and that the danger will be especially 
considerable, should they have been inundated, as is often the case in some of our 
flatter countries. The other is, that the act of breaking up such moist pasture- 
lands for cultivation, is often hazardous, as it is amply proved that malaria is 
thus produced or extricated in unusual quantity or virulence : this effect, in the 
hotter climates, being often such as to produce the almost immediate death of the 
labourers employed in it. Hence, to note a precaution as to the prevention of dis- 
ease, for which no opportunity will here occur in noticing the ordinary remedies 
against malaria, it is a matter of prudence in all such cases to break up meadow- 
lands in winter, when malaria is not produced ; or, if this cannot be done, in the 
early part of the summer, rather than in spring or autumn, the two seasons in 
which the disorders produced by malaria are most active. 
Woods, including coppices and thickets of whatever nature, comprise the next 
class of soils or places which I may notice as productive of malaria. Of the perni- 
cious properties of those in warm climates, the evidence is too abundant to admit 
of doubt. In Africa, in the East Indies, and generally in the torrid climates, 
woods, forests, jungles, bamboo and reed thickets, and many more varieties than 
1 need distinguish, are the most noted causes of the fevers which have so general- 
ly been the sources of disease, whether to permanent residents, or to armies eu. 
gaged in such territories. They are, in fact, proverbial: the question is, whether 
they are similarly pernicious in our own country. On general principles, they 
ought to be so, though, in the same proportion as any other pernicious soils are, less 
extensively and severely ; and that they are in reality injurious, is proved by a 
variety of experience. Sussex is one of the counties well known to be productive of 
autumnal fevers, and even of infermittents, if less popularly celebrated than the 
fens of Lincolnshire or the marshes of Essex. The inhabitants, at least, know 
this full well ; and he who may examine into the localities, will easily find, that 
if they not produced by the woods, there is no other cause ; while, to confirm the 
reality of this cause, I could easily point out, in various parts of England, endemic 
diseases the produce of such woods and coppices, even in districts that would be 
less suspected than Sussex. There cannot be much stronger language on this sub- 
ject, than that of a medical friend in Wales ; who, after a long residence in India, 
complains that he is still vexed by the jungle-fevex-, in the woody districts in which 
