PREFACE TO THE FIRST EDITION.

THE Constitution and the statutes of the United States, together with twelve hundred and forty-six Federal and State judicial decisions, are the principal sources from which the materials for this text-book were drawn. The most extensive treatise heretofore published on the same subject, was published in 1873; but it cited only two hundred and eighty American cases, together with one hundred and sixty-one English adjudications. The inadequacy, to the needs of the profession, of a treatise so limited in scope, was clearly impressed upon me when I entered, in 1877, upon a somewhat extended practice in patent litigation. During the next four years, I was called upon to argue several patent cases in the Supreme Court, and many others

in

many of the Circuit Courts of the United States; and in preparing those arguments, I was forced to make many laborious researches, from which a complete text-book would have largely relieved me. Under these circumstances, I resolved, early in 1881, to undertake the production of a treatise so much needed by the profession. I began writing on the first day of May of that year, and soon. became so much interested in the work, that I largely suspended my active practice of the law, in order to give the book the freshest of my efforts, and thus the greatest de

gree of merit consistent with my abilities. The result treatise covers the entire field of the patent laws of United States, as those laws were enacted in the statu and developed in the decisions, from the foundation of national government in 1789, down to the first day September, 1883. How accurately and well it covers t field, is a question which belongs to the bar and to bench; and to the generous judgment of the bench a of the bar, I commit the result of my long and interest labor.

HARTFORD, CONNECTICUT,
September 26, 1883.

A. H. W

PREFACE TO THE SECOND EDITION.

THE patent laws of the United States, as those laws exist at this beginning of the second century of the national government, are stated and explained in this edition of this book. The differences between it and the first edition, consist in omitting eleven whole sections which have become obsolete since 1883, together with parts of many other sections for the same reason; and in inserting three new sections, and many new points in many other sections, which have been enacted in the statutes or developed in the decisions since that year; and in so changing or qualifying the statements of law in many other places as to make them conform to those relevant and often radical decisions of the courts which have been rendered since the first edition of the book was published. The work of making these changes began as soon after the publication of the first edition as new decisions were published, and has continued from that time to this, and has involved my careful study and analysis of the more than six hundred new decisions which are incorporated with the more than twelve hundred old ones in the table of cited cases. The generous judgment which has been passed upon the first edition of the work, has been made known through numerous citations of the book in the decisions of the courts, and through numerous letters received by me from my professional