ON CORAL REEFS AS A CAUSE OF FEVER. 414 
its beach is girt with the graceful causarina tree. On it are 
no marshes, as far as I could observe from a short sojourn 
I made there a few years ago, which Mr J. R. Logan, who 
visited the island lately, corroborates. 
The island is girt with coral, but that is covered or only 
slightly exposed except at one point facing the south, where 
there is a village containing about 30 houses, opposite to 
which is a low shelving reef exposed at low water. The 
inhabitants of this village are afflicted with fever and ague 
(Dimam Kora) which however they attribute to spirits, not 
unlikely from seeing no visible cause on land and knowing 
not the evil indue nee of exposed coral reefs. They are very 
migratory in their habits, their occupation leading them to 
frequent the neighbouring islands in search of shells, beche 
de m£re &c. which gives them much local experience. On 
Mr Logan inquiring whether any of the neighbouring islands 
were afflicted with fever—they informed him that Pulo 
Aor was so, and that their crews very often get sick with 
DimSm Kora when visiting and lying off that island. 
Pulo Aor, 
This Pulo Aor, an island in the middle of the China Sea, 
surrounded by a vast expanse of water, is described by the 
Orang Kaya or head man of the Natunas under whose 
jurisdiction it is, as a high land with no marshes on it, 
but having an extensive coral reef on its southern aspect. 
This description of the island is confirmed by Nakoda 
Barrang a resident there who states that it is surrounded 
by coral, especially on its southern aspect; that it has no 
marshes but is covered by a low brush and jungle. The 
inhabitants of this island who live close to the beach are 
afflicted with both Dimam Kora and Dim dm Kapielu (inter¬ 
mittent and remittent fevers)—which attack them generally 
in the change of the monsoons, and when the S. W. mon¬ 
soon blows over the reef. 
Let the reader consider well the situation of this island, 
a high land, surrounded with a vast expanse of ocean, cover¬ 
ed with low brush and jungle, having no marshes—whose 
inhabitants are afflicted with fever, especially those who 
live on the beach, and during that monsoon when the wind 
blows from the sea over an exposed coral reef,—are we not 
justified in supposing that from that reef—something per¬ 
nicious does emanate ? This single illustration of my theory 
would be sufficient to arrest the attention of any ordinary 
observer. 
