From “The Sark Guide” (1845), by G.W. James:

The insular dialect — probably an antiquated form of that of the mother-island, Jersey — of course differs widely from the written language of modern France. Academicians have declared Villehardouin’s prose to be no longer French, notwithstanding the relative purity of its obsolete Champenois phraseology, as if the language of the nineteenth century were the undeviating model instead of the perverted copy! None, however, but those who have mastered the early remains of Walloon and Norman-French literature, and compared them with the vernacular speech of the Arrondissement de la Hague and the adjacent isles, analyzing each glossary with philological rigour and impartiality, can be expected to form a true conception of the merits and defects of the Low-Norman French which is still spoken in Sark. Hence the contradictory statements of many an English resident, as well as a reverend visitor from Guernsey intimately conversant with the two ‘jargons,’ if such they be. According to the former—possibly unacquainted with a refined French ‘far removed’ from its Latin and Teutonic fountain-heads — the Sark patois is ‘inarticulate and guttural;’ while, according to the latter, it is ‘the softest’ of all the outre-Manche dialects, notwithstanding the true Gaelic or Gallican, and (we might venture to add) Hibernian peculiarity of its tone. It is true that those who have been out of the island speak better French: these observations, therefore, apply to those persons who have never gone further than St. Peter-Port.