THE ORIGINS OF HORMESIS

Between 1421 and 1423 great exploratory fleets sailed from China; hundreds of junks crewed by many thousands of men set out from Nanching. Gavin Menzies, in his book 1421, vividly describes how the captains and their fleets literally explored the world, riding the great ocean currents, making discoveries that have long been attributed to later explorers. They circumnavigated the globe in great voyages that took two years and more to complete. By that time, Chinese culture was scientifically advanced and capable of making silk, brass, gunpowder and porcelain. They were also very knowledgeable about medicine, minerals and metals.

The crews enjoyed a rich and varied diet from the cultivated plants and animals kept on board the huge junks. Menzies records that they killed bugs and insects with arsenic but, remarkably, used the same poison to promote the growth of plants and silkworms. They had discovered that arsenic, while toxic at higher concentrations, also had stimulatory and beneficial effects on growth at lower concentrations. They might have assumed this to be a specific property of arsenic, but we now know that stimulation due to low concentrations of toxic substances is a general phenomenon. This discovery has been made repeatedly over the centuries for many toxic agents and a wide range of animals and plants.