A Philosophicall Essay for the Reunion of the Languages

Or, The Art of Knowing All by the Mastery of One

Duality of Voice

The Internet and Languages [around the year 2000]

Hieroglyfic

or, a Grammatical Introduction to an Universal Hieroglyfic Language

Aesthetic as Science of Expression and General Linguistic

The philosophy of life, and philosophy of language, in a course of lectures

On the Evolution of Language

First Annual Report of the Bureau of Ethnology to the Secretary of the Smithsonian Institution, 1879-80, Government Printing Office, Washington, 1881, pages 1-16

Philological Proofs of the Original Unity and Recent Origin of the Human Race

Æsthetic as science of expression and general linguistic

Opuscula

Essays chiefly Philological and Ethnographical

Introduction to the study of the history of language

Lectures on the Science of Language

Cratylus

Language

An Introduction to the Study of Speech

Language

Its Nature, Development and Origin

The Principles of Language-Study