70 
On Malaria. 
If I cannot prove, in this country, that the dunghills and pools so often found 
in farmyards and before the doors of cottages, are productive of malaria, I can at 
least quote the very decided and numerous testimonies of French physicians to this 
purpose : nor, indeed, would it often be easy to account for the fevers occurring in 
this country, and among the lower orders, without having recourse to this cause; 
while the whole analogy of the subject leaves no reason to doubt that it ought to 
be one. 
And let me make one or two remarks here which apply to all the cases of mud 
and putrefaction of whatever nature. I have already noticed that odour was not 
necessary to the existence of malaria ; and the proof "is, that while all such putre- 
fying matters, even to marshes, possess as much smell in winter as in summer, the 
poison is produced only in hot weather. The other is, as to mud, that, without any 
visible vegetation, not only does its exposure to the sun in summer produce malaria 
and fevers, but that this can be disengaged, even through the water, provided that 
it is not very deep, and without absolute exposure. Thus, in the former case, 
have some of the most severe epidemics on record been produced by the sinking 
of lakes and rivers, and the exposure of their mud ; as also happens often, and in 
the tropical climates very especially, from that brief exposure that follows the recess 
of the tide : while, in the West Indies, it is observed that fevers are invariably pro. 
duced by certain pools, as soon as they are so far diminished in depth as to al- 
low the air of the bottoms to escape through the water. Now, though our cli- 
mate is less active in this evil, these are facts of value to us in the way of pre- 
caution, while they are among tbe least suspected causes of evil ; since it has been 
ascertained, that fevers are produced where no other causes than these are present. 
1 1 '' * I notice another fact, that, in the West Indies, the mere exposure of the 
naked soil, by removing stones which covered it, has produced a sudden and deadly 
ever ; so have I, in this country, seen agues produced, immediately and decided- 
- i by the simple and iittle suspected accident of the inundation and drying of 
a celler. J 6 
But offerers produced by the exposure of mud containing vegetable matter, the 
most frequent instances in our own country are those which occur in tide harbours 
In the wanner climates, this is as notorious and deadly a cause as any one that 
ex.sts: and under this head, nothing can be more notorious than that which oc- 
curs m the t.denvcrs of Africa and the East, or within the tropics generally; 
Since tins is the very analysis of those most pestilential of all spots, mangrove sea 
, Herc ’ , there ? no > >n, p er w “h 
w hethei that lie fresh or salt, as the stems of the trees rise out of the naked mud • 
while it is ascertained by endless experience, that such a river or beacli is safe a« 
very iifstam S? ^ *** “ thTboa^ctwsat^ 
si hie, by a peculiar earthy smell 'well CaUbe 13 rendered immediately sen- 
comZ; L exports XeTo^T’^’-'T"’ a " d iusunl “ er 
they will be found to "S a " d P a ™ly by that other fact, that 
^ ~ sift 1 ft: 
tw^ s ; o „5rt«” rdTh^cttrnoSlTs to d ; sti T^ be - 
“t v 7o tn &:r sitts 
importance which is about to follow \nl alld ^ one also of very great 
portance, it is parJLlaX «y in df of this medical im- 
a »te <s ftaf rwars 
