Part 3—Chapter IX.
The Vegetable Productions of the Cordilleras.
Chinchona or Peruvian Bark.
The chinchona (it is erroneously spelt cinchona) tree constitutes the type of a natural order (Chinchonaceae), which also includes ipecacuanhas and coffees.
On the western slopes of Chimborazo, and in several other regions extending from the wooded heights of Merida and Santa Martha, at the northern end of the Cordilleras, as far as the Republic of Bolivia, 19 degrees south, the chinchona-tree has its range. Vegetation in the Cordilleras within the tropics reaches to a much greater height than in higher latitudes. The sun’s rays have there great power 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 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.