The Writer's Desk Book / Being a Reference Volume upon Questions of Punctuation, Capitalization, Spelling, Division of Words, Indention, Spacing, Italics, Abbreviations, Accents, Numerals, Faulty Diction, Letter Writing, Postal Regulations, Etc.

by William Dana Orcutt

DIPHTHONGS

1. Avoid all diphthongs, especially æ and œ, but retain æ and œ in Latin words and in nominal English forms like formulæ and other plurals, arbor vitæ, etc. Established English words having now or formerly the ligature æ or œ are generally written with the simple e.