ABSTRACT
Before the beginning of the industrial revolution, human activities were generally compatible with a healthy and sustainable biosphere. The vast majority of humans lived and worked on farms. Land was the primary source of wealth. Horses and other animals, supplemented by windmills, sails and waterwheels, provided most of the power for plowing, milling, mining and transport. 2 The sun, either directly or through products of photosynthesis, provided virtually all energy for heating and cooking, as well as food and feed. Metals were smelted by means of charcoal, but their uses were very limited and almost exclusively ornamental (in the case of gold, silver, copper and tin) or mechanical (in the case of iron and bronze). Lead was used in Roman times for water pipes and wine jars, which undoubtedly had some toxic effects on the upper classes. Only arsenic, lead and mercury, with very low melting points, had any ‘chemical’ uses – mainly as pigments, medicinais and cosmetics. Recycling of most metals was normal and quite efficient.
