What is the origin of 'sleep tight'?
Read moreOne of the mysteries of the English language finally explained.
Attributive Designating the concept that an acid is a substance that donates protons and a base a substance that accepts protons; relating to or defined by this concept.
1930s; earliest use found in Samuel Glasstone (b. 1897). From the names of Johannes N. Brønsted, Danish chemist, and Thomas M. Lowry, English chemist, who independently proposed the concept in 1923.