Amanda Yarnell

COMPETING INTERESTS Nathaniel Lubin, S. Bryn Austin, and Zachary J. Ward have been retained as experts to consult with an attorney general in social media litigation. Amanda Yarnell has received research grant support from Google. Supporting Information Filename Description nyas15345-sup-0001-SuppMat.docx1.6 MB Supporting Information REFERENCES 1 Amnesty International. (2022). Myanmar: Facebook's systems promoted violence against Rohingya; Meta owes reparations—new report.

GUNPOWDER: Alchemy, Bombards & Pyrotechnics: The History of the Explosive That Changed the World, by Jack Kelly, Basic Books, 2004, 261 pages, $25 (ISBN 0-465-03718-6) Among books that strive to show how a single substance changed the course of history, Jack Kelly's new history of gunpowder makes a compelling case.

HARVARD UNIVERSITY organic chemist William von E. Doering is a chemical legend. He is credited with, among other things, paving a route to quinine, pioneering carbene chemistry, and nailing down the mechanism of the Cope rearrangement. But his most important chemical legacy may well be his least celebrated and most lasting one: Opening China's then-insular chemistry and chemistry education communities to the West in the wake of the Cultural Revolution.