Period 6 element heavy metal, lead is a neurotoxin that accumulates both in soft tissues and the bones. Lead poisoning has been documented from ancient Rome, ancient Greece, and ancient China. Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent other metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery white color when newly made, but often seen in air with a pink tinge owing to the surface
Caduceus as a symbol of medicine a review of 257 of the works bearing this printer's device only one was related to medicine. Similar use of the caduceus in printers' marks continues to the present day, with companies including F. A. Davis Company still using the symbol as an element of their insignia. There are a few other examples of use in this period. It may have been used as a symbol by Sir William Butts, physician to Henry VIII. Similarly, physician John Caius, founder of Caius College, Cambridge, and at the time President of the Royal College of Physicians, during official visits to his eponymous