What is a Chemical Element? A Collection of Essays by Chemists, Philosophers, Historians, and Educators: edited by Eric Scerri and Elena Ghibaudi, New York, NY: Oxford University Press, 2020, 312 pp., ISBN: 9780190933784, £65.00.

Mercury oxide does not contain two simple bodies, a gas and a metal, but two elements, mercury and oxygen, which, when free, are a gas and a metal. A Collection of Essays by Chemists, Philosophers, Historians, and Educators: edited by Eric Scerri and Elena Ghibaudi, New York, NY: Oxford University Press, 2020, 312 pp., ISBN: 9780190933784, £65.00 To wit, the number of known elements grew from 33 elements in Lavoisier's time to no less than 63 elements in Mendeleev's time. [Extracted from the article]