of quinine is
absolutely necessary. Since the discovery of the medicinal properties
of this bark, it has proved an inestimable blessing to the human race.
For many years the bark itself was used as a febrifuge; but quinine,
which is extracted from it, is of still greater value in curing or
preventing ague. On various occasions it has rendered great service by
preserving the health of troops. Many lives were saved by it in the
disastrous Walcheren expedition. In India it is now universally used
with the same beneficial effect; and several African explorers have been
enabled to prosecute their journeys through pestiferous regions by its
frequent use. Dr Livingstone, among others, speaks of it as the chief
remedy he has employed when attacked by sickness on his journeys.

Most of the Chinchonae, when growing in good soil, and under favourable
circumstances, become large forest-trees. When crowded, they frequently
run up to a great height without a branch; while at the upper limit of
their zone, they become mere shrubs.

There are numerous species of chinchona, producing bark of greatly
different values. There are upwards of nineteen different species of
the true Chinchonae, and upwards of seventy once received as such,
though now considered of no commercial value. The three characteristics
by which the true chinchona may be known are--the presence of curly
hairs bordering the laciniae of the corolla; the peculiar mode of
dehiscence of the capsule from below upwards; and the little pits at the
axils of the veins on the under sides of the leaves. The leaves are of
a great variety of shapes and sizes. In the finer species they are
lanceolate, with a shining surface of bright green, traversed by crimson
veins and petioles of the same colour. The flowers are very small, and
hang in clustering panicles like lilacs. They are generally of a deep
roseate colour, paler near the stalk, and dark crimson within the tube,
with white curly hairs bordering the laciniae of the corolla. The
colour of one species is entirely white. They send forth a delicious
fragrance, which scents the air in their neighbourhood.

The region round the little town of Loxa, on the southern frontier of
Ecuador, is the original home of the chinchona. In its sheltered
ravines and dense forests were found those precious trees which first
made known to the world the healing virtues of Peruvian bark. They grow
at a height above the sea of from 62