Iodine was discovered within seaweed ash (kelp) by the French chemist Bernard Courtois. In October 1813 the British chemist Humphry Davy (1778 -1829) and his wife, accompanied by Michael Faraday as his scientific assistant traveled to France. Whilst in Paris Davy was asked to investigate the substance isolated by Courtois. Davy showed it to be an element, and it was given the name Iodine. The name is from the Greek iodides for violet. Iodine crystals give off, when heated, a violet vapour with an irritating odour.