439 
ON CORAL REEFS AS A CaUSE OF FEVER. 
the natives of the country cannot reside there with impunity % 
one of the most conspicuous of them is Port Bremer, a land- 
locked harbour to the eastward of Port Essington, the shores 
of which are so pregnant with malaria, that the natives never 
take up their abode there, and the Macassar trepang fishers, 
who have resorted to it, on one or two occasions suffered 
so much from fever, that although the harbour abounds with 
Trepang they avoid it most scrupulously. The upper parts 
o( the inner harbour of Port Essington are also regarded 
with great dread by the Macassars, who previous to our arri¬ 
val invariably anchored their prahus at Point Record, although 
the Trepang is only found in large quantities within the inner 
harbour.” 
tfC During nearly four years subsequent to the occupation of 
Port Essington, very few cases of fever, aud not one of death, 
occurred among the garrison, but towards the close of 1842 
fevers generally tertian, became prevalent, and when I left the 
settlement in September last year, 1 believe that not a single 
individual residing there had been entirely free from attacks. 
These generally had not been very violent, 6 cases only having 
terminated fatally, but the mortality was sufficiently great to 
cause a considerable degree of uneasiness on the part of the 
authorities. We at first supposed that this liability to sick¬ 
ness arose from the constitutions of the men having become 
impaired by long residence in a tropical climate ; but it was 
found that individuals who had recently arrived were equally 
subject to attacks of fever and ague.” 
# This last sentence fixes the cause of the fever to some¬ 
thing connected with the locality. This something is ac¬ 
cording to Mr Earl “ malaria engendered by mangrove 
swamps and by mud banks exposed at low water/' but know¬ 
ing that this “alone is insufficient to give rise to the insalu¬ 
brity that affects certain spots, from the fact that Singapore 
near the southern extremity of the Malay Peninsula, and 
Sourabaya the capital of the eastern districts of Java, 
are very unfavourably situated in this respect, and are 
at the same time the most healthy of all the European 
settlements, in the Indian Archipelago,” “ the only peculia¬ 
rity in their position that tends to afford a clue to the mys- 
tery, consists in their being situated upon narrow straits 
through .which the tide flows with great rapidity/’ I allow 
that a rise and fall of tide has great ameliorating effects on 
sea mud flats and mangrove marshes, and that a narrow 
strait where the current of water will be accelerated, will add 
to the good effects, but the ingenious explanation is far from 
sufficient, in which the talented and sensible author I believe 
