Once a Week (magazine)/Series 1/Volume 8/Peruvian bark and the trees which yield it

From Wikisource
Jump to navigation Jump to search

PERUVIAN BARK AND THE TREES WHICH YIELD IT.

 

 

On the slopes and in the ravines of the Andes, in the more northern parts of South America, within the tropics, but at elevations where the climate is temperate, in scattered groups amidst dense forests, or, higher on the mountains, singly and in clusters on the ridges where the guanaco and vicugna feed, grow the trees of the genus Cinchona, natives of no other part of the world, but yielding a medicine of inestimable value, and with which, as a remedy for the intermittent fevers of warm and moist countries, no other febrifuge is worthy to be compared. For these trees, and these alone, produce the long celebrated Peruvian bark, and Peruvian bark is the only source of quinine.

We are apt to wonder that a boon so precious should have been bestowed in this way, instead of being lavished at once on the inhabitants of all quarters of the globe. But a little reflection shows that this is at least no exceptional instance of its kind, but accordant with a great general law of creation and providence. When we inquire into the distribution of the different kinds of plants and animals existing in the world, we find that most of them are natives only of certain countries; and even those which, because of their long-proved value, have been most widely diffused through the care and agency of man, appear to have been at first limited to some of the early seats of civilisation. And thus scope has been afforded for the cultivation of man’s own faculties, and for the beneficial exertion of all human energies.

It seems probable that the medicinal properties of the bark of the cinchonas were known to the Indians before the Spanish conquest, although a long time elapsed ere they communicated their knowledge to their conquerors. The Jesuit missionaries on the upper tributaries of the Amazon were perhaps the first Europeans who became acquainted with the nature of this bark, and towards the end of the seventeenth century they began to send parcels of it to Rome. Hence it received the name of Jesuits’ Bark. Cardinal Juan de Lugo distinguished himself by his endeavours to promote its use; and the name Cardinal’s Bark was therefore often given to it. It was also called Countess’s Bark, from the Countess of Cinchon, or Chincon, wife of the Viceroy of Peru, by whom it was brought to Spain as early as 1640, although it did not then get into extensive reputation or use. She had been cured by it, two years before, when she lay ill of a severe intermittent fever at Lima: and to her physician its value had been made known by the Corregidor of Loxa, who himself, in similar distress, had received information of it from an Indian.

Whilst this medicine was still scarcely known in Europe, except among the Jesuits of Spain and Italy, an Englishman, Sir Robert Talbor, or Talbot, having become acquainted with it, acquired a great reputation for his wonderful success in the cure of intermittents. Louis XIV. of France purchased the secret from him for two thousand louis d’ors, a large pension, and a title, and immediately made it public. The price was at first enormous, one hundred louis d’ors a pound. But the fame of Peruvian Bark was now established, and it soon became an important article of commerce. Some, indeed, of the physicians of the time derided it, and repelled the innovation, as in more recent times a few have been found to oppose the introduction of chloroform. But all controversy on this subject ceased at an early date in the eighteenth century; and so great was the demand for Peruvian Bark, that even in 1735 apprehensions were entertained of the probable extirpation of the trees producing it in the forests of Loxa, where alone they were then known to exist. The first botanical description of a Peruvian Bark tree was published shortly afterwards by the French botanist De la Condamine, and the name Cinchona was given to the genus by Linnæus, in commemoration of the Countess of Cinchon.

The Spanish Government, towards the end of last century, sent botanical expeditions to explore the forests of different parts of South America, in order to the discovery of bark trees; but through the influence of parties interested in maintaining a commercial monopoly, the value of some of the new species discovered was concealed, and large quantities of bark which had been collected were destroyed; and thus, through a vile cupidity and a mistaken political economy, one of the most useful of medicines was kept at a price which placed it beyond the reach of multitudes to whom it would have proved a blessing.

The discovery of quinine or quinia, one of the alkaloids to which Peruvian Bark owes almost all its medicinal value, and by far the most important of them, took place in the beginning of the present century. The name of quinine is now familiar to every one, and its value not only in the cure of intermittents, but as a tonic medicine, is universally recognised. Great quantities of Peruvian Bark are now consumed in the preparation of quinine, and the question of an abundant supply becomes every day more urgent; for hitherto the demand has increased far more than the supply. What the value of Peruvian Bark is, was proved in the unfortunate Walcheren expedition, in the saving of many lives by the opportune arrival of an American ship with a large quantity of it. Poor sufferers, emaciated with fever and shaking with ague, were speedily restored to health. The introduction of quinine into the military hospitals of India was immediately followed by a great diminution of the mortality from fevers. The quinine used in the hospitals now costs the Government of India many thousands of pounds sterling annually. In the Confederate States of North America, after the beginning of the present war, quinine was eagerly purchased for its weight in gold: and the smuggling of this medicine across the frontier, or by ships which run the blockade, has been as much watched against by the Federalists as the importation of any of the munitions of war. For the exclusive possession of quinine, if it were possible for them, would give great advantage to one of the contending parties, in a country where intermittent fever is often more formidable to an army than the weapons of the enemy.

The abundant supply of Peruvian Bark is, therefore, a question of deep interest to mankind. Every species of cinchona of which the bark is really valuable, is now eagerly sought after, wherever it grows; but the districts once most productive of bark now produce comparatively little; all the regulations by which the South American Governments have from time to time attempted to prevent the destruction of the trees, have been nearly ineffectual; and in all South America no attempt has ever been made for their cultivation. The collecting of the bark is the occupation of persons called cascarilleros. The word is a diminutive of the Spanish cascara, bark; and Peruvian Bark itself is in Peru commonly called cascarilla. These cascarilleros are trained to this occupation from their childhood. Their life is a hard one; they suffer great privations and expose themselves to great dangers, proceeding in quest of bark trees over high mountain passes, to regions far from the habitations of men. The life of the cascarillero, if less exciting, is not less perilous than that of the chamois-hunter of the Alps; and the scenes amidst which it is spent, are more varied, and at least as grand and awful. Before reaching the region where they propose to search for bark trees, the cascarilleros often pass over the highest ridges of the Andes. Their ordinary practice, when they have reached a suitable locality, is to ascend to an elevated pinnacle of the mountains, or to climb one of the highest trees of the forest, in order to obtain an extensive view. They readily recognise the cinchonas by their foliage, even from a great distance, and with wonderful accuracy proceed to the spot where they grow.

But of course no cascarillero feels an interest in preserving the trees for future years. His present interest is to procure as much bark as he can from that wild forest or high mountain ridge, for the merchant who employs him, and to whose warehouse, in some seaport of the western coast, he must carry it over passes where, although within the tropics, he confronts the dangers of snowstorm and avalanche, and where the thin air is scarcely sufficient for his unaccustomed lungs, travelling on the verge of precipices where a false step would make him food for the condor. Sometimes, too, the cascarillero wanders in the forest, and some subsequent traveller may find his bones and his bundles of bark, where, hungry and exhausted, he renounced all hope, and laid himself down to die. No wonder, therefore, that the government regulations for the preservation of the trees receive little attention, and that, although these trees grow readily again from their stools, the men who find them in the lonely wilderness take all that they can, destroying the stools, and barking the very roots for present gain.

That no plantation of cinchonas has yet been attempted in South America is a sad sign of the state of the countries which yet regard these trees as an important part of their national wealth, and exhibit a ridiculous eagerness to prevent any exportation of plants or seeds of them. It is not wonderful that the introduction of them into countries suitable for their cultivation should have been attempted: it is rather wonderful that the attempt should not have been earnestly made long ago. The botanist De la Condamine, indeed, endeavoured to carry plants of a species of cinchona, the first of which the medicinal value was known, from Loxa to the Jardin des Plantes at Paris in 1743, or 1744; but after he had conveyed them, with much trouble, down the Amazon, a wave washed over his little vessel near Para, and carried off the box in which he had preserved them for more than eight months, and in which he had brought them more than two thousand miles. It does not appear that any earnest effort was ever made to procure plants or seeds of these valuable trees with a view to their cultivation in any part of the world, till the Dutch government sent a botanist named Hasskarl to Peru in 1852, to procure them for Java. It had for at least thirty years been urged on the Dutch government by men of science that an endeavour of this kind should be made, the mountains of Java being regarded as very suitable for the cinchonas. Similar recommendations were addressed to the government of British India, particularly by the late eminent Dr. Royle; and these were at last acted upon after Dr. Royle’s death, a commission being given to Mr. Markham in 1859, to procure plants and seeds of cinchonas, and to convey them to India. How well this commission was executed, and amidst what difficulties, may be learned from the volume of travels recently published by Mr. Markham,[1] and still more unquestionably from the success of the cinchona cultivation begun in India. The Neilgherry Hills were chosen as the place to which the greater part of the cinchona plants and seeds should be sent. Some were, however, also sent to the mountains of Ceylon, and to Darjeeling, in the Sikkim Himalaya. And already there are thousands of plants of the best species of cinchona in India; plants are freely sold from the government nurseries to those who are willing to undertake the cultivation of them; and amongst the many joint-stock schemes which have recently been presented to the capitalists of Britain, one not undeserving of favourable regard is for the cultivation of cinchonas on the Neilgherry Hills.

The Dutch have been less successful in Java; principally, it would seem, because the plants and seeds which they obtained were mostly those of a worthless species of cinchona. They did, however, introduce into Java two valuable species, of which the Indian cultivators have been glad to obtain plants in exchange. And cinchonas of the most valuable kinds, and suited to different climates, may now be regarded as fully introduced into India, Ceylon, and Java. The fact is equally delightful, when viewed from the positions of the political economist and of the philanthropist. It is to be regretted that, although the Indian government, with praiseworthy liberality, sent a portion of the plants and seeds, collected at its expense, to Jamaica, little attention has been paid to them in that island, the mountains of which seem a most likely place for their profitable cultivation. We may feel sure that the introduction of these trees into other countries will prove beneficial to South America itself. The present monopoly enriches only a few capitalists. Driven to compete with the rest of the world, in the supply of an article, the demand for which will rapidly increase with the reduction of the price, South Americans may also seek to render it more abundant by the cultivation of the trees in their native regions, with the happy results of employment and remuneration to great numbers of people, and an increase of national prosperity and human happiness.

It only remains for us to say a few words concerning the Peruvian Bark trees, and the alkaloids which they produce. The Peruvian name of these trees is Quina, or Quinquina, a modification of which, China, was long in general use among apothecaries and others, and is still in general use in some countries of Europe. Of the genus Cinchona, as established by Linnæus, nearly one hundred species are known, natives of various tropical countries, although abounding chiefly in the tropical parts of America. It has been divided, however, into a number of genera, and although the botanical characters by which some of them are distinguished very nearly approach those of the group for which alone the name Cinchona is now retained, it is an interesting fact that beyond the limits of that group no trace has been found of the peculiar alkaloids which give medicinal value to Peruvian Bark, whilst all the species of that group produce them in greater or less abundance. Apparently trivial distinctions, therefore, acquire importance from their observed relation to most valuable products and properties. Curly hairs on the margin of the segments of the corolla are one distinction of the true cinchonas; whilst another is the splitting of the ripe seed-vessels from the base upwards, and not from the apex downwards. And by these characters they may be at once discriminated from many trees very nearly resembling them. Of the genus, as thus restricted, about twenty species are known, all of them found in the Andes, between the nineteenth degree of South latitude and the tenth degree of North latitude; whilst it is further remarkable that the particular species have very limited latitudinal and altitudinal zones, within which alone they occur. The cinchonas of New Granada are not only different from those of the south of Peru and Bolivia, but even from those of intermediate latitudes: and in like manner the traveller, in ascending or descending the mountains, finds one species to appear, and another to disappear, as he passes a certain altitudinal line. None of the cinchonas are found at an elevation of less than 2500 feet above the sea, and some extend as far up the mountains as 9000 or 10,000 feet. Of this adaptation of different species to climates considerably different advantage is likely to be taken in order to their cultivation in different parts of the world. Even the south of Europe might probably be suitable for some.

These valuable trees are also trees of great beauty. Some of them grow to a considerable height, and are fine umbrageous trees; and others grow up as straight and leafless as palms; while some are mere shrubs, scattered over grassy slopes and plains at great elevations among the mountains. They have evergreen, laurel-like leaves; their flowers have a general resemblance to those of lilac, which, however, they excel in beauty, and diffuse around the trees a delicious fragrance. If South America had a native poetry, these trees could not but have a poetic celebrity.

Peruvian Bark yields to the chemist not fewer than five alkaloids, of which no other source is known, not even in trees of the genera most nearly allied to the true cinchonas. These alkaloids are Quinine, Cinchonine, Quinidine, Cinchonidine, and Arecine. The proportion in which they exist in different kinds of bark, produced by different species of cinchona, or under different circumstances, is very various. Of the alkaloids themselves, Quinine is the most valuable, and Cinchonidine, much more recently discovered, is said to be next to it.

 

  1. “Travels in Peru and India, while Superintending the Collection of Chinchona Plants and Seeds in South America, and their Introduction into India.” By Clements R. Markham, F.S.A., F.R.G.S., &c. London. 1862.