588 ON CORAL REEFS AS A CAUSE OF THE, FEVER 
via or emanations from dead animal matter in a slate of decom¬ 
position, is eminently unhealthy, cast: par : 3rd. That in the ab¬ 
sence of all other causes, the coral reef in front of Ayer Banderli 
is the cause of the endemic remittent, and intermittent fever, that 
has cut off so many, and still attacks all the residents in the said 
locality. 
On examining more minutely, I found that in the N.E. mon¬ 
soon, which I have shewn blows during half the year, and which 
blows over these reefs, there is more unhealthiness than in the other 
season, while during the S.W. monsoon, whose winds blow over the 
island, the inhabitants are comparatively healthy. This is from three 
causes. 1st. from the direction of the wind being directly over the 
decomposing coral reefs. 2nd. daring that monsoon more rainy 
Weather occurs, it being the wet monsoon, the deaths among the 
living Polyps will therefore be greater than during the dry monsoon, 
and so furnish more matter for decomposition. 3rd. in the N.E. 
monsoon the weather is much more changeable and the vicissitudes 
in the thermometrical and hygrometrical state of the atmosphere 
much greater than during the S.W. monsoon ; for these reasons in 
any situation, independent of the coral, the climate would be more 
unhealth v. 
Two reasons exist for this Ayer Bandera being more obnoxious to 
fever than any other locality near Singapore. The first is: the winds 
during the N.E. monsoon which waft the poison from the two coral 
reefs are prevented by the Flag Staff hill from diffusing it, they there¬ 
fore strike on the abrupt face of the hill and fall in a concentrated 
state on the devoted heads of those who have their residences betwixt 
the base of the hill and the beach. During the S.W. monsoon the 
wind cannot affect the reefs immmediately below the hill, on account 
of its height: and therefore instead of a wind carrying away the poi¬ 
sonous emanations, and diffusing and so rendering them innocuous by 
diluting them with the surrounding atmosphere, there is a fatal lull 
which allows the sea breeze by day to bring to the land the efluvium 
which would otherwise be diffused. The 2d. cause which renders 
it obnoxious is the rapid current which runs betwixt Blakang Mati 
and Pulo Brani, sometimes at the rate of 7 miles an hour; opposite 
to Ayer Banddra the channel is deep and narrow, but suddenly in¬ 
creases so that in $ths. of a mile it widens from the |th to the fths. 
of a mile by which the velocity of the current is much decreased, 
and detached coral or animal and vegetable matter is thrown on 
