Читать книгу The Greatest Benefit to Mankind: A Medical History of Humanity - Roy Porter - Страница 54

THE MOST MOMENTOUS EVENT FOR HUMAN HEALTH was Columbus’s landfall in 1492 on Hispaniola (now the Dominican Republic and Haiti). The Europeans’ discovery of America forged contact between two human populations isolated from each other for thousands of years, and the biological consequences were devastating, unleashing the worst health disaster there has ever been, and precipitating the conquest of the New World by the Old World’s diseases.

The forebears of the ‘Indians’ Columbus encountered in his attempt to find a short-cut to the ‘Indies’ or China were hunter-gatherers. Before or around 10,000 BC such people had crossed the Bering Straits from Asia to Alaska via a land bridge created by the fall in sea levels during the last Ice Age. They were relatively disease-free; lacking domesticated animals, they had no walking disease-carriers except themselves, and on their travels they encountered no other humans.

The melting of the great North American glaciers isolated that continent while opening it up to the newcomers, who spread south. In time the Maya, Aztec and Inca to the south and the Mississippian peoples of North America settled into sedentary agriculture, cultivating maize and beans, cassava and potatoes, and in some cases building complex civilizations centred on vast cities – which spawned all the familiar health problems. Tuberculosis developed, as did pinta and other treponemal infections, including non-venereal syphilis, various disorders caused by intestinal parasites, and Chagas’ disease. With agriculture came the nutritional maladies typical of monocultures.

The Amerindian peoples developed their own forms of medicine, with priests, shamans and sorcerers conducting healing rituals. Supernatural powers were believed to inflict pestilence to punish misdeeds, and in Mexico and Peru disease was connected with witchcraft and the malevolent shades of dead animals, demons and deities. Native Americans acquired knowledge of the healing properties of various vegetable products: Peruvian Indians chewed coca leaves against hunger and fatigue, while cacao (cocoa) was the Aztecs’ most important tonic and medicinal beverage, powdered and boiled in water with honey, vanilla and pepper. The Incas had herbs for headaches and other pains; and they used scopolamine, a poison from the datura plant, as an anaesthetic. Broken bones were treated with fat from the ñandu, an ostrich-like bird, and llama kidney juice was dropped into aching ears.

North American Indian tribes had a less extensive materia medica. They used sassafras, holly, sunflower seeds and infusions of flaxseed, inhaled the smoke from burning twigs to treat chest conditions, and used decoctions of mushrooms and peyote as hallucinogens. A Spanish explorer, Cabeza de Vaca, travelling in the 1520s through what is now Texas, observed the healing practices of the native Indians: ‘their method of cure is to blow on the sick, the breath and the laying-on of hands supposedly casting out the infirmity.’ He had no doubt what to think of that: ‘We scoffed at their cures.’

The New World peoples were not living in a golden age, but they had been spared Eurasian afflictions. Thus they were vulnerable virgin soil, entirely without resistance to epidemics imported by the conquistadores. This was not the first time Spanish conquest had brought diseases to a virgin population. In the fifteenth century, the Iberian conquest of the Canary islands had meant total devastation of the native inhabitants, the Guanches, whose immune systems were helpless against European infections. Originally there were some 100,000 Guanches; by 1530 only a handful was left, and in the seventeenth century they became extinct, spectacular victims of what has been called ecological imperialism.

The first epidemic, which struck Hispaniola in 1493, may have been swine influenza, carried by pigs aboard Columbus’s ships. Other deadly diseases then struck in hammerblows, so that New World populations were reeling even before smallpox reached the Caribbean in 1518. That outbreak killed one third to one half of the Arawaks on Hispaniola and spread from there to Puerto Rico and Cuba. A few Spaniards fell sick but none died and, as ever, all was attributed to God’s will, in support of the Christian conquest.

Smallpox accompanied Hernan Cortés (1485–1547) to Montezuma’s Aztec Mexico, where the main town was Tenochtitlan (modern Mexico City); with some 300,000 people, it was three times the size of Seville. Contact spread the disease among the natives outside the city and then within. In 1521, Cortés attacked with 300 Spaniards. Three months later, when the city fell, the conqueror learned that half its people had died, including Montezuma and his successor: ‘a man could not put his foot down unless on the corpse of an Indian.’ The same happened when Pizarro (c. 1475–1541) took on the Incas: smallpox ran ahead of him to Peru. By 1533, when he entered Cuzco to plunder its treasure, the Incas were incapable of serious resistance.

Infections thus primed and sped conquest, rippling outwards to fell countless indigenes the Spanish troops did not have to butcher. The consequent epidemics did not merely exterminate vast numbers, they destroyed the will to resist – the psychological impact was as devastating as the physical. Between 1518 and 1531, perhaps one third of the total Indian population died of smallpox, while the Spanish hardly suffered. With allies like microbes, the Europeans did not require many soldiers or much military acumen.

These initial smallpox outbreaks were only the beginning of a long, mainly unintentional, but almost genocidal germ onslaught unleashed against the Amerindians. Waves of measles – 1519 (Santa Domingo), 1523 (Guatemala) and 1531 (Mexico) – influenza, and finally typhus followed, all bringing devastating mortalities. In 1529 measles killed two thirds of those who had just survived smallpox; two years later it had killed half the Hondurans, ravaged Mexico, raced through Central America and attacked the Incas. Repeated epidemics followed, one of the worst being that of typhus, which towards 1600 killed about two million people in the Mexican highlands. By then, 90 per cent of the local inhabitants had died in successive outbreaks, and the fabric of life had fallen to pieces.

Though the mainland populations of Mexico and the Andes gradually recovered, in the Caribbean and in parts of Brazil decline verged upon extinction; from as early as 1520, the Spanish imported slaves from Africa to meet the labour shortages in their lucrative Peruvian silver mines. African slaves, in turn, brought malaria and yellow fever, creating further disasters. Guns and germs enabled small European bands to conquer half a continent in what might be called, to echo Gibbon, another victory of barbarism over civilization.

In later centuries the North American Indian population was similarly devastated by the English and French, sometimes by the fiendish distribution of smallpox-infected blankets and clothes. In 1645, smallpox killed half the Hurons; the same happened later with the Cherokees in the Charleston area, and with the Omahas and the Mandans. Not one European fell sick of smallpox in 1680, when the Revd Increase Mather (1639–172 3) tersely recorded that ‘the Indians began to be quarrelsome … but God ended the controversy by sending the smallpox among the Indians’. The wholesale destruction of indigenous New World populations continued for over three hundred years; twenty million slaves had to be shipped to America to fill the vacuum, causing cruelty and suffering on a scale not matched until the regimes of Hitler and Stalin.