Osmium was discovered in 1803 by smithson tennant. It was discovered because earlier experimenters assumed it was graphite but he suspected it was something else and had began to investigate it.Tennant added platinum to dilute aqua regia, and observed that not all the metal went into solution. By a combination of acid and alkali treatments he eventually separated it into two new metal elements, which he named iridium and osmium, naming the latter on account of the strong odour it gave off. Its name is derived from osme the Greek word for smell.
