Bartsch's law


In historical linguistics, Bartsch's law or the Bartsch effect is the name of a sound change that took place in the early history of the langues d'oïl, for example in the development of Old French.

Description

Bartsch's law was a phonetic change affecting the open central vowel in northern Gallo-Romance dialects in the 5th-6th century. This vowel, inherited from Vulgar Latin, underwent fronting and closure in stressed open syllables when preceded by a palatal or palatalized consonant. The result of this process in Old French was the diphthong :
Note that is also the outcome of the diphthongization of in stressed, open syllables:
The chronology of Bartsch's law relative to the more general diphthongization of to has not been conclusively established. According to one view, diphthongization took place first, and Bartsch's law is seen as a further segmentation of the diphthong caused by the preceding palatal/palatalized consonant, followed by simplification of the resulting triphthong:
According to a second view, Bartsch's law affected the simple vowel, causing it to change to, which then diphthongized to :
Support for the second hypothesis comes the fact that palatal consonants triggered the same change > in unstressed word-initial syllables:

Further development

Subsequent changes have obscured the effects of Bartsch's law in modern French. The accent shifted to the second element of the diphthong, and the first element underwent glide formation:
The glide was then lost in most words, either absorbed by the preceding palatal consonant, or eliminated by analogical pressure :
The glide was only retained if subsequent nasalization took place, as in Modern French chien "dog".
Consequently, the vowel "e" in these words, which is due to Bartsch's law, is now indistinguishable from the "e" that resulted from the general diphthongization of . The diphthong is still visible in the spelling of words like chien "dog" and moitié "half".