Mémoire sur le système primitif des voyelles dans les langues indo-européennes

Written in 1878, while the author was a twenty-year-old student in Berlin, Saussure's only full-length work proposed the existence of two additional sonant coefficients in the Indo-European parent language. Applying the methods of comparison and internal reconstruction to Proto-Indo-European, Saussure argued that the long vowels had developed from a short vowel plus a sonant coefficient. A hypothe...