I contemplate in this work a description of the comparative organization of the languages enumerated in the title page, comprehending all the features of their relationship, and an inquiry into their physical and mechanical laws, and the origin of the forms which distinguish their grammatical relations. One point alone I shall leave untouched, the secret of the roots, or the foundation of the nomenclature of the primary ideas. I shall not investigate, for example, why the root I signifies “go” and not “stand”; why the combination of sounds STHA or STA signifies “stand” and not “go.” I shall attempt, apart from this, to follow out as it were the language in its stages of being and march of developement; yet in such a manner that those who are predetermined not to recognise, as explained, that which they maintain to be inexplicable, may perhaps find less to offend them in this work than the avowal of such a tendency might lead them to expect. In the majority of cases the primary signification, and, with it, the primary source of the grammatical forms, present themselves to observation in consequence of the extension of the circle of our knowledge of languages, and of the confronting of sister bases separated for ages, but bearing indubitable features of their family connection.