For all that has been set down the writer is alone responsible. He is, however, keenly mindful of all the co-operation that has been given him, and it would be most pleasant if it were possible to relate by name those who have been of aid. Mere words of thanks could but very little express the sense of obligation that is felt towards all of these. Indeed, one of the most delightful features connected with the work has been the response which as a rule has been elicited by the writer's inquiries; and in some cases so courteous and gracious have been the correspondents and informants that one might at times think that a favor were being done them in the making of the request. To certain ones the writer cannot escape mentioning his appreciation: to Dr. E. A. Fay, editor of the _American Annals of the Deaf_, and vice-president of Gallaudet College; Dr. J. R. Dobyns, of the Mississippi School, and secretary of the Convention of American Instructors of the Deaf; Mr. Fred Deland, of the Volta Bureau; Mr. E. A. Hodgson, editor of the _Deaf-Mutes' Journal_; Mr. E. H. Currier, of the New York Institution, and Dr. T. F. Fox and Mr. Ignatius Bjorlee, also of this institution; Dr. Joseph A. Hill, of the Census Bureau; Mr. Alexander Johnson, formerly secretary of the National Conference of Charities and Corrections; Dr. H. H. Hart, of the Russell Sage Foundation; Professor S. M. Lindsay and Dr. E. S. Whitin, of Columbia University; and to the officials of the Library of Congress, of the New York Public Library, of the New York State Library, of the New York School of Philanthropy Library, of the New York Academy of Medicine, of the Columbia University Library, of the Volta Bureau, and of the Gallaudet College Library. CONTENTS PAGE INTRODUCTION xiii PART I POSITION OF THE DEAF IN SOCIETY CHAPTER I. THE DEAF IN THE UNITED STATES 3 Meaning of Term "Deaf" in the Present Study--Number of the Deaf in the United States--Age when Deafness Occurred--Ability of the Deaf to Speak--Means of Communication Employed by the Deaf. II. THE DEAF AS A PERMANENT ELEMENT OF THE POPULATION 13 Increase in the Number of the Deaf in Relation to the Increase in the General Population--The Adventitiously Deaf and the Congenitally Deaf--Adventitious Deafness and its Causes--Possible Action for the Prevention of Adventitious Deafness--Adventitious Deafness as an Increasing or Decreasing Phenomenon--The Congenitally Deaf--The Offspring of Consanguineous Marriages--The Deaf Having Deaf Relatives--The Offspring of Deaf Parents--Possible Action for the Prevention of Congenital Deafness--Congenital Deafness as an Increasing or Decreasing Phenomenon--Conclusions with Respect to the Elimination or Prevention of Deafness.