From this impulse arose the movement which, widened and directed by much practical experience, has culminated in the preparation of the Oxford English Dictionary, 'A new English Dictionary on Historical Principles, founded mainly on the materials collected by the Philological Society.' This dictionary superadds to all the features that have been successively evolved by the long chain of workers, the historical information which Dr. Trench desiderated. It seeks not merely to record every word that has been used in the language for the last 800 years, with its written form and signification, and the pronunciation of the current words, but to furnish a biography of each word, giving as nearly as possible the date of its birth or first known appearance, and, in the case of an obsolete word or sense, of its last appearance, the source from which it was actually derived, the form and sense with which it entered the language or is first found in it, and the successive changes of form and developments of sense which it has since undergone. All these particulars are derived from historical research; they are an induction of facts gathered by the widest investigation of the written monuments of the language. For the purposes of this historical illustration more than five millions of extracts have been made, by two thousand volunteer Readers, from innumerable books, representing the English literature of all ages, and from numerous documentary records. From these, and the further researches for which they provide a starting-point, the history of each word is deduced and exhibited. Since the Philological Society's scheme was propounded, several large dictionaries have been compiled, adopting one or more of Archbishop Trench's suggestions, and thus showing some of the minor features of this dictionary. They have collected some of the rare and obsolete words and senses of the past three centuries; they have attained to greater fullness and exactness in exhibiting the current uses of words, and especially of the many modern words which the progress of physical science has called into being. But they leave the _history_ of the words themselves where it was when Dr. Trench pointed out the deficiencies of existing dictionaries. And their literary illustrations of the older words are, in too many cases, those of Dr. Johnson, copied from dictionary to dictionary without examination or verification, and, what is more important, without acknowledgement, so that the reader has no warning that a given quotation is merely second-or third-hand, and, therefore, to be accepted with qualification[15]. The quotations in the New English Dictionary, on the other hand, have been supplied afresh by its army of volunteer Readers; or, when for any reason one is adopted from a preceding dictionary without verification, the fact is stated, both as an acknowledgement of others' work, and as a warning to the reader that it is given on intermediate authority.