The era of exploration: health and the tropical climate before 1800

The four journeys to the Americas undertaken by Columbus inaugurated the era of European expansion, conquest and colonisation. The soldiers, explorers and settlers who came to the Americas brought with them a number of contagious diseases to which Europeans had gradually acquired resistance over a period of several centuries.

During the centuries following the discovery of the New World, European nations greatly expanded their trade networks and established colonial empires around the globe. As a consequence, the circulation of humans, commodities, animals and plants around the world increased significantly, and European diets were greatly enriched. From South America, potatoes, sweet peppers, tomatoes, maize and peanuts were imported to Europe. These vegetables were much more nutritious and contained more vitamins than the food Europeans ate at the time. Later, Europeans imported coffee and cacao from Africa and a wide variety of herbs and spices, of which nutmeg, cloves and pepper were the most important, from Asia.

The new era of colonial expansion in many locations led to the introduction of new diseases, which threatened both indigenous populations and individuals involved in the colonial venture. The long ocean voyages to reach colonial trading posts were unusually perilous: the lack of fresh fruit and vegetables led to outbreaks of scurvy and beri-beri, which claimed the lives of many crew members. Mortality in new colonial settlements was very high—and would remain very high until the beginning of the twentieth century. There were times when fewer than half of new arrivals survived even for one year. Finding ways to counter the challenges disease posed became essential for colonialism to succeed and many physicians attempted to find solutions. Not surprisingly, attitudes towards the tropics were highly ambivalent and oscillated between, on the one hand, an admiration of the natural beauty, extreme biodiversity and the untold riches that could be acquired there and, on the other hand, a denunciation of hostile, unhealthy and at times lethal nature in the tropics.³ Physicians were consulted on ways to preserve lives during the long voyages overseas, maintain the strength of colonial armies and guard the health of colonial settle­ments in the new possessions. To accomplish this, they initially explored indigenous approaches to health and disease, developed theories on the possibilities and limitations to European settlement in the tropics and proposed hygienic measures to safeguard the health of traders, colonial administrators and settlers.

European expatriates were often bewildered when they encountered foreign lands and their inhabitants. The flora and fauna were different from those at home; the people were different and spoke incomprehensible languages; their religion was unusual and strange, as was the way in which they conducted their everyday life. Otherness was everywhere and disturbing. The small number of European physicians who resided in the early trading posts eagerly studied indigenous medical practices in the hope that these might contain cures for the most common local diseases. The first work describing the medicine of the East was Coloquios dos simples e Drogas (Conversations on Simples and Medications) by the Portuguese physician Garcia de Orta (1501?—1568), which was published in 1563 in the Portuguese trading port of Goa in India. While de Orta was practising in Goa he explored local medicinal traditions, relying on the insights of local informers such as indigenous healers, spice traders and his own personnel. The exploration of local medical practices was based on the belief that the indigenous population had found ways to deal with the diseases common in particular areas. Following local habits in diet, lifestyle, hygiene and medical care would thus improve health conditions in Europeans as well. In 1642 De Medicina Indorum (About Indies Medicine), written by the Dutch physician Jacobus Bontius (1592—1631), appeared detailing the insights he acquired during the four years he spent in Batavia (today’s Jakarta), the headquarters of the Dutch East India Company (Vereenigde Oost-Indische Compagnie or VOC). The text described many diseases that had been closely observed in the field and investigated through autopsies conducted following battles and epidemics of dysentery and beri-beri. Physicians in the colonies were engaged in many different pursuits and became important investigators of tropical spaces and their specificities.

Many physicians conducted research into the geography, flora and fauna of the newly explored areas, often with an eye to commerce.

Before 1800, health was viewed as a balance between an individual and his or her environment. This balance was influenced by an individual’s diet, habits and morality as well as environmental variables such as sudden changes in temperature, chills and precipitation. In the eighteenth century, several physicians and natural philosophers developed theories about the influence of climate on the human constitution. Many of them thought that the human frame was flexible and its characteristics fluid. Individuals acquired those traits that enabled them to survive in a given environment.