international pictogram for toxic chemicals. The<unk>  stretches from before 4500 BCE to the present day.<unk> s have been used for many purposes across the span of human existence, most commonly as weapons, anti-venoms, and medicines.<unk>  has allowed much progress in branches, toxicology, and technology, among other sciences.<unk>  was discovered in ancient times, and was used by ancient tribes and civilizations as a hunting tool to quicken and ensure the death of their prey or enemies. This use of<unk>  grew more advanced, and many of these ancient peoples began forging weapons designed specifically for<unk>  enhancement. Later in history, particularly at the time of the Roman Empire, one of the more prevalent uses was assassination. As early as 331 BCE,<unk> ings executed at the dinner table or in drinks were reported, and the practice became a common occurrence. The use of fatal substances was seen among every social class; even the nobility would often use it to dispose of unwanted political or economic opponents. In Medieval Europe,<unk>  became a more popular form of killing, though cures surfaced for many of the more widely known<unk> s. This was stimulated by the increased availability of<unk> s; shops known as apothecaries, selling various medicinal wares, were open to the public, and from there, substances that were traditionally used for curative purposes were employed for more sinister ends. At approximately the same time, in the Middle East, Arabs developed a form of arsenic that is odorless and transparent, making the<unk>  difficult to detect. This<unk>  epidemic" was also prevalent in parts of Asia at this time, as well. Over the centuries, the variety of harmful uses of<unk> s continued to increase. The means for curing these<unk> s also advanced in parallel. In the modern world, intentional<unk> ing is less common than the Middle Ages. Rather, the more common concern is the risk of accidental<unk> ing from everyday substances and products. Constructive uses for<unk> s have increased considerably in the modern world.<unk> s are now used as pesticides, disinfectants, cleaning solutions, and preservatives. Nonetheless,<unk>  continues to be used as a hunting tool in remote parts of developing countries, including Africa, South America, and Asia.
History of poison
History of herbalism
History of dermatology
History of dental treatments
History of pathology
History of chemical warfare
History of medical diagnosis
History of smallpox