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The Middle Ages contributed a great deal to medical knowledge. This period contained progress in surgery, medical chemistry, dissection, and practical medicine. The Middle Ages laid the ground work for later, more significant discoveries. There was a slow but constant progression in the way that medicine was studied and practiced.
Many metals, particularly heavy metals are toxic, but some are essential, and some, such as bismuth, have a low toxicity. Metals in an oxidation state abnormal to the body may also become toxic: chromium(III) is an essential trace element, but chromium(VI) is a carcinogen. Only soluble metal-containing compounds are toxic.
Copper was probably the first metal mined and crafted by humans. [8] It was originally obtained as a native metal and later from the smelting of ores. Earliest estimates of the discovery of copper suggest around 9000 BC in the Middle East. It was one of the most important materials to humans throughout the Chalcolithic and Bronze Ages.
The first cause of cancer was identified by British surgeon Percivall Pott, who discovered in 1775 that cancer of the scrotum was a common disease among chimney sweeps. [ citation needed ] The work of other individual physicians led to various insights, but when physicians started working together they could draw firmer conclusions.
1900 – Swedish Dr. Stenbeck cures a skin cancer with small doses of radiation [4] 1920s – Dr. William B. Coley's immunotherapy treatment, regressed tumors in hundreds of cases, the success of Coley's Toxins attracted heavy resistance from his rival and supervisor, Dr. James Ewing, who was an ardent supporter of radiation therapy for cancer.
A toxic heavy metal is a common but misleading term for a metal-like element noted for its potential toxicity. [4] Not all heavy metals are toxic and some toxic metals are not heavy. [ 5 ] Elements often discussed as toxic include cadmium , mercury and lead , [ 6 ] all of which appear in the World Health Organization 's list of 10 chemicals of ...
An average 70 kg human body is about 0.01% heavy metals (~7 g, equivalent to the weight of two dried peas, with iron at 4 g, zinc at 2.5 g, and lead at 0.12 g comprising the three main constituents), 2% light metals (~1.4 kg, the weight of a bottle of wine) and nearly 98% nonmetals (mostly water). [51] [n 8]
Even as the Middle Ages become increasingly well documented; historians increasingly focus on writing literature addressing some of the primary misconceptions about medieval history; [2] [3] and other historians take the alternative approach of highlighting many of the intellectual, scientific, and technological advances that took place during ...