inventions: Asia and the Pacific 577 shone, Potawatomi, and other Great Basin North American groups as oral contraception; kelp, used by Indians throughout the Americas to treat goiters and other iodine deficiencies; and ipecac, used by Mesoamericans and Amazonians to induce vomiting and cleanse the intestines of parasites The American peoples were generally conscientious in their observance of personal hygiene Locating their residences near fresh or running water was an intentional decision, but Indians went far beyond bathing in their daily cleansing rituals Most North American peoples washed and removed stains from their clothes using various forms of vegetable and herbal detergents; Mesoamericans used both copal and fragrant oils as underarm deodorants; and both the Inca and Aztec used frayed, fibrous tree cuttings to brush their teeth People on all the American continents used some manner of toothpaste, usually made of a mildly abrasive mineral, such as salt, charcoal, or ash From maple syrup to salsa and tortillas, most modern Americans are familiar with the legacy of Native American foods to the colonists that followed Less familiar are the facts that Caribbean Indians invented the barbecue method of cooking meat sometime in the first millennium and that the indigenous people of Canada and Alaska were the first seafarers to engage in open-sea whaling Fishing methods were particularly unique in the Americas Many Indians from California to the Caribbean used poisonous chemicals to capture fish Derived from plant sources like yams and manioc, the poisons had no effect on people, making this chemical fishing technique both expedient and safe Ice fishing, with spears through holes in the Arctic ice sheets, was yet another unusual method of fishing pioneered by Native Americans Some Indian agricultural innovations, such as the domestication of corn, were already millennia old by the advent of the Common Era But Native Americans continued to experiment with plant species, not always to increase their food supplies Many centuries after domesticating corn, American Indians began to domesticate cotton The Mexican variety would go on to out-compete all other varieties of cotton on the modern world market Other Native American innovations were in methods of cultivation rather than the crop itself Increasingly, archaeologists have begun to speculate that perhaps the Amazon rain forest, for all its wild, “virgin” appearance, may be partially anthropogenic, that is, influenced by humans Indians may have selected certain tree species for planting in specific areas of the Amazon, thereby increasing the density of useful species while maintaining the appearance and ecology of the original rain forest Concentrations of fruit-bearing species or trees that attract certain types of animals favored in hunting would be made to grow together, all for the harvesting convenience of the Indians who lived nearby These deliberately planted trees are discernible only when counted, which is precisely how some scholars have concluded that certain groups of Amazonian trees are the result of human agency Other recent studies provide evidence that precolonial Amazonians manipulated their environment in this inconspicuous way Terra preta is a dark soil with extremely high fertility that Amazonian farmers seem to have developed through a process of phased mulching, whereby a reproducing bacterial cycle is set in motion, causing the soil to remain perpetually fertile Modern farmers have located sites that repeatedly yield this rich soil and have begun either selling the terra preta or trying to reproduce its mysterious recipe Because pottery and other centuries-old human products have been found in terra preta deposits, archaeologists are without doubt that this self-replenishing soil was purposefully engineered by Indians for use in the raised-bed agriculture of the Amazon Asia and the Pacific by Caryn E Neumann Arguably the most important inventions of the medieval era originated in Asia and the Pacific These inventions appear to have been entirely empirical rather than rooted in scientific theories—ad hoc creations and not the products of large numbers of technicians dedicated to the process of invention Until Europe advanced after the 13th century, China led the medieval world in technological advancements The compass, mechanized printing, and gunpowder all are Chinese inventions that proved critical to the growth of the modern world As Chinese culture spread throughout Asia and the Pacific, these major Chinese inventions spread as well One of the greatest Chinese inventions, the compass, removed much of the power of weather from travel With the compass a mariner could set sail at any time, since clouds that obscured the sky were no longer a factor to consider The compass could always identify the position of Polaris, the primary star used in navigation The device is built on the magnetic power of the lodestone, which had been identified by both the ancient Greeks and the ancient Chinese The lodestone consists of magnetite, a natural oxide of iron that exhibits magnetic properties By the sixth century the Chinese scientifically passed the Europeans by discovering the phenomenon of induced magnetism A piece of metal could be magnetized by stroking it periodically with a lodestone The Chinese discovered the declination as well as the polarity of the magnet by the eighth century These developments made the invention of the compass possible By the 11th century the Chinese were using the compass for navigation This