This eBook has been formatted to the highest digital standards and adjusted for readability on all devices. Over the period of two years author has devoted the intervals between official duties to collecting and collating materials for the study of sign language. As the few publications on the general subject, possessing more than historic interest, are meager in details and vague in expression, original investigation has been necessary. The high development of communication by gesture among the tribes of North America, and its continued extensive use by many of them, naturally directed the first researches to that continent, with the result that a large body of facts procured from collaborators and by personal examination has now been gathered and classified.