ON THE MEDICAL TOPOGRAPHY OF SINGAPORE. 487 
hydrogen is a much more delicate one than Professor Gardi¬ 
ner’s. 
In the spots where sulphuretted hydrogen abounds according to 
my observations no fever exists. To arrive at this conclusion I have 
made lepeated and repeated enquiries on that point, amongst a class 
of natives who live entirely in small boats in the river, and canals 
just alluded to, sleeping there without fail, wherever their avocations 
may lead them to during the day. These natives are Chinese and 
Malays. The latter are regularly domesticated in their boats, then- 
wives seldom venture on shore, except to see some festivals, or pur¬ 
chase a little finery, and when they do so they seem really to be 
out of their element. The children are brought into the world, 
brought up, and leave it, in their boats, and to complete their isolation 
although they are Malays yet their patois is so peculiar as only to 
be understood by themselves. These natives are without an excep¬ 
tion free from fever. The inhabitants of the houses that skirt the 
canals and the river are also exempt from fever, though I cannot 
say positively that occasionally it may not have attacked some. But 
the strongest proof of all, is that there is a canal which skirts the 
east side of the Jail within a very few yards of the building and 
which canal at all times emits sulphuretted hydrogen gas, but twice 
a day at low water to such an extent as to be almost unbearable by 
the inmates from the stench, and which gas blackens in one hour pa¬ 
per saturated with carbonate of lead, suspended a few feet above the 
water, yet for all that not one inmate of the Jail from July 1844 to 
March i 848, died of fever, as may be seen by the following table. 
