338 
ON THE CAMPHOR-TREE OF SUMATRA. 
is not swampy. It is found most abundantly, and in the best state 
on the out-lying hills of the mountain-chain and on the lower slopes 
of the mountains themselves, at a height of from three to five hun- 
dred feet; and here the camphor is collected in the greatest quantity 
The camphor-tree was seen by Dr. Junghuhn on the promonto- 
ry of Caracara, near Telo; on the alluvial plain of Loemoet, 
on the mountains of Hoeraba, behind Sibogha ; and on the ridges 
of hills in the south of Loemoet, &c. He found it growing on 
weather-beaten granitic and trachytic hills, on yellow-red clayey 
soil, abundantly furnished with oxide of iron, and also on a rich 
alluvial soil abounding with humus. 
Climate and Temperature of the region of the Camphor-tree. — 
On the coasts the mean annual temperature is but 80 9 (on the 
island of Java 82°,) and nearly 78° Fahr. at 1000 feet, the most 
elevated limits where *he tree is still found, thus much lower than 
in Java. 
There are two causes particularly, that bring about this depres- 
sion of temperature : first, the narrowness of the level shore of the 
coast, immediately at the foot of high mountains ; secondly, the un- 
interrupted dense forests, w 7 ith which not only the mountain-chain 
itself, but the coast-plain is covered. These circumstances produce 
a greater humidity, and at the same time a greater coolness of the 
air, at an inferior elevation, than in Java. 
At the eastern foot of the Sumatra mountain-chain there are ex- 
tensive arid and barren plains, only overgrown with alang-alang 
(e. g., at Pertibi.) Over the heated soil of these plains the air be- 
comes extraordinarily rarified : the cooler sea-air rushes in, com- 
ing from the ocean on the western side of Sumatra, wmere the sea 
is deep, and where no land exists for a great distance ; and a west 
wind arises, which, partly kept back by the obliquely situated 
mountain-chains, changes into a north-western one. This wind 
carries the humidity of the sea towards the mountains, by the sum- 
mits of which the moisture is soon condensed and changed into 
clouds. These, during the whole year, at intervals almost daily, 
at regular hours, but chiefly in the afternoon, shed heavy showers 
over the land, while the thunder roars in the mountains. The 
dampness of the air is then so great, that mist and clouds are for 
many days seen hanging immoveably even over the woods of the 
lower coast-lands. Frequently, too, the wind blows by reverber- 
