45 S 
ON THE MEDICAL TOPOGRAPHY OF SINGAPORE. 
Many tropical countries have an equal quantity of rain, ami even 
more, annually falling'; but owing to the fall being chiefly confined 
to one time of the year, an equal benefit with Singapore is not re¬ 
ceived, nay even it is tbe occasion of much disease when the rain is 
followed by great heats (Twining) ; the rain falling here in showers 
throughout tbe year and not confined to one season, gives a perpe¬ 
tual verdure to vegetation, cools the surface of the earth, and preci¬ 
pitates, as well as tends to diminish the generation of any atmos¬ 
pherical Malaria. 
The jungle ever green and loaded with moisture, cools the cur¬ 
rents of air that blow over it, giving us the pleasant and refreshing 
evening breeze, while the island of no great extent, elevated towards 
the centre and declining towards the coast, by its numerous small ri¬ 
vers, pours into the ocean the extra moisture which the vegetation 
and the thirsty soil fail to take up, by which all stagnation is prevent¬ 
ed and marsh miasma is but little generated, except in a few spots. 
Tlie state of dryness of the atmosphere, or that quantity of mois¬ 
ture which it can absorb, is very great in this island. I cannot from 
any observations of my own shew the absolute quantity of moisture 
contained in our atmosphere, hut the familiar deliquescence of com¬ 
mon salt, to such an extent that unless daily dried by heat it becomes 
fluid, the rusting of all iron instruments, the starting of wood made 
in Europe, and the separation of pieces merely glued, with the run- 
ing of ink on ordinary paper, are all too common instances of the 
great dampness of tins climate. This solution of moisture in the 
atmosphere is a point of much importance in considering the sub¬ 
ject of contagion, for wherever you have beat and consequent mois¬ 
ture, you have decomposition quickly accelerated. Malaria or miasm 
finds in moisture an excellent medium of transmission, and from the 
statistics of tropical countries it is well knowm that wherever 
there is much moisture there is a corresponding increase of diseases. 
“ If we reckon by Fahrenheits’ Divisions, air absolutely humid holds 
at the limit of congelation the hundred and sixtieth part of its 
weight of moisture ; at 59° the eightieth part; at that of 86° 
the fortieth part; at 149° the tenth part,” (Encyclopsedia Brit.) 
