In search of the fever tree: Mark Honigsbaum follows the trail of Richard Spruce, one of hunters, who set off into the forests of Ecuador in 1860 roja or red bark tree -- the cure then, as it is now, for malaria. (In The Footsteps)(Cover Story).
Now you are poised above the cloud forest at 3,000 metres looking towards the `southern sea', as the Spanish conquerors of Ecuador called the Pacific Ocean. Enjoy the view. The next 1,200 metres are almost straight down.
Even for someone in the peak of physical condition the trail is gruelling, but for Richard Spruce, a British botanical explorer who passed this way in June 1860, it should have been next to impossible. Two months before he set off to cross Chimborazo, Spruce wrote that he was seized by a sudden `rheumatic and nervous affliction' that left him paralysed in the `back legs'. The attack could not have come at a worse time. Spruce had just been entrusted by the British government with the most important commission of his career -- the collection of seeds and plants of the precious cascarilla roja, or red bark tree of Ecuador, the source then, as now, of the anti-malarial quinine.
In 1860 quinine was the only cure for malaria, and Britons beset by disease and civil disorder in India were desperate to secure their own supplies. With the Ecuadorian bark forests nearly exhausted as a result of the frantic stripping of trees to satisfy European demand for the drug, the transplantation of cinchona -- to give the tree its correct botanical name -- was no longer viewed simply as a matter of colonial self-interest but a humanitarian imperative. For only in India, argued the British, could cinchona be raised in sufficient quantities to satisfy the needs of humankind.
Spruce was not the first botanist to go in search of cinchona and by no means the only Briton. From the 18th century onwards a succession of European explorers and plant collectors came to South America with the aim of wresting the famous `fever tree' from its native Andean soil and making a gift of it to their sovereigns. But for one reason or another, all these early botanical raiding parties failed. In 1741, Frenchman Charles-Marie de la Condamine succeeded in harvesting several fine young cinchona plants in southern Ecuador and sailing down the Amazon with them, only to lose his entire collection when a wave swept over his boat in Brazil. Spanish and Dutch expeditions to, respectively, Peru and Bolivia, suffered similar fates and by the middle of the 19th century the leading European powers were growing desperate.
It was against this background that the British government decided to organise a series of collecting missions to gather the eight most valuable species of cinchona growing in the Andes. The missions were coordinated by Clements Markham, then a young historian and linguist attached to the India Office, who is best remembered today as the patron of Robert Falcon Scott's second, tragic expedition to the Antarctic. Markham pointed out that as the Old World had contributed to the New "such priceless gifts as wheat, barley, rice, cattle and horses", it was only right the Andean republics should grant Europeans cinchona in return. Today, of course, anyone who dared voice such arguments would be accused of botanical piracy, but so terrible was the problem of malaria in India, that Markham and Spruce's missions made them heroes.
It was in an effort to understand the challenges facing these cinchona pioneers that last year I found myself standing on the rim of Chimborazo's glacier, looking west towards the Ensillada and the pass of Llullundengo -- a tiny v-shaped cutting that guards the descent to the cinchona forests. My goal was the ridge where in 1860 Spruce succeeded in collecting 100,000 cinchona seeds and more than 600 young plants of cascarilla roja, later despatching them via Panama, Britain and the Red Sea to Mysore, where they became the backbone of the Indian quinine plantations.
According to a map Spruce drew in 1860 to illustrate the account of his expedition, the ridge should lie some 1,800 metres below Lullundengo, overlooking the river Limon. But the names of the villages and rivers have all changed and I had to enlist the help of Robert Kunstaetter, a Canadian who specialises in offbeat treks in Ecuador, to make sure we did not get lost. My aim was to be as faithful as possible to Spruce's expedition and so Robert hired mules to transport our packs over Chimborazo and a guide to scout the trail to the ridge.
Oddly for someone recently debilitated by illness Spruce does not seem to have suffered soroche -- the throbbing headaches and nausea that often accompanies travel at these altitudes. Nevertheless, his journey was an ordeal. James Taylor, a British doctor living in Ecuador, persuaded Spruce to rise from his sickbed in Ambato and make the expedition to the cinchona forests, promising him that he would find the Pacific breezes on the other side of the Andean cordillera `reviving'. But no sooner had Spruce set off than he regretted the decision. "Not to interrupt the rest of my narrative with the continual groanings of an invalid," he wrote, "I may say here, once for all, that ... I was but too often in that state of prostration when to lie down quietly and die would have seemed a relief."
Spruce and Taylor rode from Ambato by horse, crossing the sierra to Mocha, where they transferred to mules for the trek around the southern shoulder of Chimborazo. We set off from Urbino, the old railway station house built by the British in 1908, which now serves as a lodge for climbers planning assaults on the `monarch of the Andes'. Spruce's paralysis had left him so weakened that on the first day out he needed two long rests, and by nightfall he and Taylor were still picking their way over the paramo of Sanancajas. We made better progress and by sunset were already camped high on the edge of the glacier at 3,900 metres where "a slender meniscus of cloud, assuming exactly the form of the cope of the mountain" clung to the summit, just as Spruce had described it in 1860.
Despite the compensations of the view, Spruce writes that the descent from Llullundengo was "the most precipitous and dangerous" he had ever negotiated, and standing in the cutting at 3,000 metres I could see what he meant. The trail is not so much a track as a near-vertical mud ladder rutted with camel-humps from the constant passage of animal hooves. Spruce hired cabrestillos -- sturdy Andean bulls -- to negotiate these obstacles, but the bulls have long since disappeared and we had to rely on our own powers of ambulation.
For the first 500 metres or so I felt like Jack scrambling down the beanstalk. No sooner had we crossed the pass than thick cloud engulfed the hillside and it began to drizzle, turning the trail into one long mud-chute. For two hours we gingerly picked our way over the humps, feeling the way ahead with our poles. Then the fog lifted and our perspective was transformed. The trail was peppered with every colour in nature's palette: yellow calceolariae, blood-red melastomacae and, every now and again, a bromeliad, its fiery tentacles reaching for the sky. Humming birds flitted above our heads, but most spectacular of all was the view: a dramatic series of ridges and v-shaped valleys, falling towards the horizon.
While Spruce was negotiating the descent to Limon, Markham had already completed his mission and despatched his collection of cinchonas from the Pacific coast of Peru. Accompanied by an expert horticulturalist, John Weir, Markham had arrived in Peru in January 1860 and travelled directly to Puno, on the shores of Lake Titicaca. From there he crossed the eastern Andean cordillera to Sandia and descended a series of equally precipitous ridges and valleys until he arrived at the Tambopata river, in the distant south-eastern Peruvian province of Carabaya.
Markham's original intention had been to cross into Bolivia where the species with the highest quinine content of all -- Cinchona calisaya -- grew. But Peru and Bolivia had just declared war and there was no guarantee that the Bolivians, already alert to the threat of foreigners plundering their bark trade, would allow him back across the border. Markham gambled that the Peruvians would be less suspicious. However, no sooner had he reached the Tambopata valley than a former Peruvian army officer alerted locally elected officials to Markham's purpose and began whipping up the Indians who made their living from stripping cinchona bark in the forest. Faced with having his collection confiscated, Markham had no choice but to foreshorten his mission and return to the coast as quickly as possible. To avoid arrest, he set a direct compass course from Sandia across the high Andean plateau to Vilque, wrapping the cinchonas in his poncho at night to prevent them withering in the sub-zero frosts on the paramo.
After a brief stand-off with customs at the port of Islay and a half-hearted attempt at sabotage by some disgruntled Peruvians, Markham succeeded in loading 500 plants into his Wardian cases -- the portable greenhouses used to transport plants overseas -- and despatched them to Britain via Panama. Watching the Isthmus recede from view, Markham could barely contain his sense of achievement.
"It could not but be satisfactory to look back upon the extraordinary difficulties we had overcome," he confided in his journal. "The hardships and dangers of the forests, the scarcity of the plants, the bewildering puzzle to find them amidst the dense Underwood, the endeavour to stop my journey ... and then to see the great majority of the plants budding and looking healthy in the Wardian cases. So far as our work in South America was concerned, it had been performed with complete success." But Markham's celebrations were premature. Although more than 200 cinchonas reached Southampton alive, in crossing Egypt in October the plants were incinerated in the heat of the Red Sea. On arrival at the government plantations in India the entire collection was dead.
Fortunately for the British, Spruce had better luck. After two days, gingerly picking his way down the trail from Llullundengo, he found himself in a clearing above the Rio Limon where he spied a group of three red bark trees in full flower. The species, known as Cinchona succirubra, was exactly what Spruce was looking for. With the help of Robert Cross, an expert gardener from Kew, Spruce spent the summer camped on the ridge patiently collecting succirubra seed capsules and propagating cuttings. He and Cross then loaded some 600 plants onto a raft and sailed downriver to Guayaquil where a steamer was waiting to take them to Britain. Those plants -- patiently cared for at Kew Gardens before being shipped to India -- were the ones that thrived in the government plantations.
Over 140 years later the cinchona forest in Limon is long gone, but many of the descendants of Spruce's trees can still be found on the ridge where he and Cross assembled their collection. With my guide, I found a particularly fine specimen sprouting from the stump of an older, felled tree. I tie snoot was silvery-white and the trunk completely free of moss -- an indication of the bitterness of the quinine in the bark which helps discourage plant predators. The most striking aspect of the tree, however, was its leaves -- a mixture of deep green and bright crimson. "Cinchona succirubra is a very handsome tree," wrote Spruce, "and in looking out over the forest I could never see any other tree at all comparable to it for beauty."
But succirubra bark contained too little quinine to make the extraction of the compound commercially viable in India. Instead, the bark was used to prepare a decoction of all the cinchona alkaloids, known as `totaquinine' (in addition to quinine, cinchona bark contains the anti-malarial alkaloids quinidine, cinchonine and cinchonidine). Later, Spruce's trees were also used as a rootstock for another species of cinchona, named Cinchona ledgeriana after Briton Charles Ledger, who succeeded in transplanting them from Bolivia to the Dutch East Indies.
Several years after Markham and Spruce completed their missions, the Dutch discovered that Ledger's trees had the highest quinine content of all and began farming the bark on such a scale that they soon had the world market for quinine cornered. But that, as they say, is another story.
Mark Honigsbaum's book, The Fever Trail: The Hunt for the Cure for Malaria, is published by Macmillan on 11 November
In November 2000, Mark Honigsbaum rashly quit his job as chief reporter on The Observer and disappeared into the jungles and cloud forests of South America. Travelling in the footsteps of three Victorian quinine explorers in the Andes, Mark ventured deep into the Venezuelan Amazon and over the volcano Chimborazo, in Ecuador. The result of his endeavours can be seen this month with the publication of The Fever Trail: The Hunt For The Cure For Malaria. In a specially adapted article for Geographical beginning on page 41, he tells the story of two quinine hunters -- Richard Spruce and Clements Markham -- and their expeditions in search of cinchona, the tree whose bark, then as now, is the source of the powerful anti-malarial.
MEDICINE FROM NATURE
Quinine is not the only plant-derived alkaloid to have revolutionised the medical treatment of disease. Other plant-based medicines, include:
Morphine: a derivative of opium, obtained from the juice of the seedpods of the opium poppy, Papaver somniferum. First isolated by a German chemist in 1803 -- 17 years before quinine -- morphine is named after Morpheus, the God of dreams, and is one of the most powerful painkillers known to man.
Taxol: derived from the bark of the Pacific Yew, Taxus brevifolia, taxol emerged in the 1980s as a revolutionary new treatment for ovarian and breast cancer. Synthetic derivatives of the alkaloid are now also being used to treat lung cancer and Kaposi's Sarcoma.
Acetylsalicylic acid (aspirin): the Greek physician Dioscorides first recommended the juice of the willow tree as a decoction for gout. Over 1,800 years later, chemists discovered that willow juice's analgesic action was due to the presence of a compound called salicin. Modified to salicylic acid, it proved effective against skin diseases, and modified again it became acetylsalicylic acid -- the powerful analgesic known as aspirin.
Colchicine: an alkaloid derived from plants of the genus Colchicum, especially from the corns of the autumn crocus, Colchicum autumnale. It prevents the accumulation of uric acid crystals in the body, making it useful to treat gout. It also inhibits mitosis, or cell division -- hence its application to cancer therapy.
Digitalis: a cardiac glycoside, derived from foxglove, Digitalis purpurea. Now a common treatment for congestive heart failure, foxglove was first used in 1775 by William Withering, an amateur botanist from Stafford, to treat dropsy (edema).
Artemisinin: a complex molecule derived from the fragrant herb, Artemisia annua (wild wormwood) or quing hao in China. First mentioned as a cure for fevers in a 4th century Chinese medical handbook, quing hao was `rediscovered' by Chinese scientists in the 1970s. The Chinese showed that the compound, quing hao su, was faster than quinine at clearing malaria. Artemisinin and its derivatives are now recommended as emergency treatments for some strains.
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|Date:||Nov 1, 2001|
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