wer in heating the
soil; while the mists drawn from the broad Pacific, rising above the
plains, rest upon the lofty sides of the mountains. The warm and humid
atmosphere thus created is especially favourable to the growth of
certain trees and shrubs. Among others is the chinchona-tree, from
which quinine is obtained. It is generally found growing at a height of
from 6000 feet to 10,000 feet above the ocean.

It would have been strange had not the native Peruvians been acquainted
with the qualities of the bark. The Quichua name for the tree,
_quina-quina_--"bark of barks"--shows that they believed it to possess
medicinal properties; indeed, there is little doubt that they were aware
of its febrifugal qualities, though they might not have attached much
importance to them. Through them, probably, the Spanish colonists in
the neighbourhood of Loxa first discovered its virtues. It was,
however, but little known till the year 1638, when the wife of the Count
of Chinchon, Viceroy of Peru, lay sick of an intermittent fever in the
palace of Lima. The corregidor of Loxa, who had himself been cured of
an ague by the bark, hearing of her sickness, sent a parcel of powdered
quinquina bark to her physician. It was administered to the Countess
Anna, and effected a complete cure. She, in consequence, did her utmost
to make it known. Her famous cure induced Linnaeus long afterwards to
name the whole genus of quinine-yielding trees Chinchona, in her honour.
The Jesuit missionaries, who had learned its virtues, also sent parcels
of the bark to Rome, whence it was distributed to members of their
fraternity throughout Europe by the Cardinal de Lugo. Hence it was
sometimes called Jesuits' bark, and sometimes Cardinal's bark. For many
years, however, great opposition was made by European physicians to its
use. Some Protestants, indeed, went so far as to decline taking it,
because it was favoured by the Jesuits. Although the bark was used for
many years, it was not till Dr Gomez, a surgeon in the Portuguese navy,
in 1816 isolated the febrifugal principle, and called it chinchonine,
that its true value became known. But the final discovery of quinine,
as it is now used, is due to the French chemists Pelletier and Caventon,
in 1820. It is a white substance, without smell, bitter, fusible, and
crystallised.

Chinchonine is of less strength than quinine, and is used in mild cases
of intermittent fever; but in severe cases, the use