What is the origin of 'sleep tight'?
Read moreOne of the mysteries of the English language finally explained.
proper noun
(1881–1945), German organic chemist. He determined the structure of the porphyrin group of many natural pigments, including the red oxygen-carrying part of haemoglobin, the green chlorophyll pigments found in plants, and the orange bile pigment bilirubin. Nobel Prize for Chemistry (1930).
