IN the First and Second Parts of the present work, its principle, namely, the dialectic character of the Confusion of Tongues at Babel, and the consequent reducibleness of all the original post-diluvian dialects to the one primeval language, has been experimentally tested and verified at Sinai and in Egypt: fields of inquiry, in which the antecedent presumptions, and the actual phenomena, meet together to establish the proof of this principle, in ways, and with a completeness, without parallel in any third example.