ON COHAti REEFS AS A CAUSE OF FEVER. 420 
came down when I told him; he died two hours after. In 
fact out of all the crew, captain, officers and men, only 2 
lived to return to Batavia and those were affected with fever, but 
neither I nor my coolies were affected in the slightest degree. 
W. C. Leisk. 
Note .—The men in the boats were first attacked, and there 
was no fever at that time amongst the shipping. 
W. C. L. 
This communication clearly shows that the virulence of 
the endemic has not of late years diminished, Edam being 
still as unhealthy as it was in 1800. But all must not bo 
attributed to the miasm from the island, as the labour of load¬ 
ing the boats had predisposed the men who were in them to 
receive the impressions of the malaria, and had curtailed the 
latent stage, and perhaps the nature of the ballast being coral 
might, if all decomposition had not ceased, have kept up the 
malarious influence. Notwithstanding all this I would not 
insist that all the malaria was derived from Edam, for altho* 
there was at that time no disease of a febrile nature amongst 
the shipping in Batavia harbour, yet might the crew of the 
tc Atiet Bachman’’ have there received the first of the seeds 
of infection which were afterwards augmented and perfected 
at Edam. 
This febrile influence is not floating about indiscriminately, 
but is to be found in greater strength and virulence near the 
islands than at some some distance from them,—for since 
my attention has been directed to this subject I have made 
inquiries of masters of vessels who had left Batavia as their 
last port, and I have found that as their vessels were anchored 
near Onrust or Kuypers island, so was the greater chance of 
fever and its amount; while the vessels that escaped were 
those that were anchored midway betwixt the islands and the 
pier of Batavia, or out at sea at some distance from the 
islands and the town. 
Pursuing my investigations as to the present state of the 
islands and harbour of Batavia, Mr Riley, long a resident 
there, thus replies to my queries. tf Onrust still continues 
unhealthy, the Dutch Government were and most likely are 
still constructing additional works and a dock there, and the 
native labourers there employed—Javanese, Malays, Malayan 
Chinese, &c., were dying off* as quick as ever they were known 
to do on former occasions- If Europeans escape at present more 
tolerably than in former days, it must be attributed to an im¬ 
proved style of living, and the exercise of greater precautions 
than of yore. Still the influence of the climate is plainly per¬ 
ceptible in the majority of those who reside at the customs/* 
