I flatter myself that enough hath been say'd to convince all that are open to conviction, that the ancient British language (now called Welsh) was one and the same in the main with that of ancient Gaul, now France... 


JLhvyd and Pexron, those prodigies of Celtic knowledge, and Boast of British Antiquaries, had not then appeared on the stage of Literature. The former of these, by his Comparative Entymology which makes a part of his celebrated Archceologia Britannica, hath pointed out a method of, and laid down very easy rules for, reducing all the ancient and modern tongues of Europe to one general source and common origin. The latter; in his Antiquite de la Langue et de la Nation de Celtes, hath proved, by his amazing skill in languages and history, that this common origin of the European tongues, was no other than the ancient Celtic; and that again derived from the Gotnarian and Iaonian or Ionic, the languages of Gomer and Javan the sons of Japhet after the confusion at Babel: that the Celtic was the language of the Titans, a great and warlike nation, who spread themselves not only over all the Loner Asia, but also over the greatest part of Europe, and under their princes, Acmon, Uranus, Saturn, Jupiter, Mars, &c. erected a vast empire, and made their language universal; of which language the Greek, Latin, Teutonic, Gaulish, British, Irish, Welsh, French &c. are but different dialects, somewhat disguised and altered by mutual intermixtures, by the different pronunciation of different countries and the polishing refinement of Grammarians. In the course of his researches, this learned Armorican has given the entymologies of proper names, of rivers, towns, mountains, &c. in the countries over which the Titan empire extended itself, as also those formerly inhabited by the Gauls, the descendants of the Titans. And these, most of them at least, so naturally resolve themselves into Celtic, i.e. British, etymons, that, they seem to me to carry conviction along with them that they are derived from that alone, and from no other language.

...the exquisitely learned and amazingly industrious M. Bulle, who in his 'Memoirs sur la langue Celtique', "appears to have made some progress," as a professed Critic expresses it, "in all the languages of the earth." This Gentleman has run the same course as Perzon, but has outstript him in the race, and advanced so far beyond him as to make the Celtic to be a dialect of the original language communicated by the Creator to the first Parents of mankind. And admitting the primitive languages to have been the Hebrew, which, I fancy, very few will dispute, he is not singular in his opinion; for a very learned person of our own Nation, in his Enquires concerning the first inhabitants, Language, &c. of Europe, published about the same time, supposes the Celtic a sister-dialect of the Hebrew...
                      [An English and Welsh Vocabulary, or, an Easy Guide to the Ancient British Language: pg.29 copyright 2011 www.general-books.net]