The immense debt which the foregoing pages owe to the _Oxford English Dictionary_—now practically complete—is, I hope, too obvious from the text to need further emphasis. Without access to that unrivalled monument of imaginative scholarship a great deal of the first part, and nearly all the second part, of this book could never have been even attempted. Readers who wish to study history in English words for themselves should lose no opportunity of consulting its fascinating volumes. And in case the fear of wearisome repetition has induced me to mislead, I should like to take advantage of this opening to point out that the _O.E.D._ is the authority for practically all the English etymological and semantic material on which my book is based. For example, the incautious but conveniently brief statement that such a word “was first used by” Chaucer or “first appeared in” the fourteenth century must be regarded as the abbreviated form of a longer statement to the effect that the earliest illustrative quotation given in the _O.E.D._ under the heading of the word in question is drawn from Chaucer or from a book written during that century. On the subject as a whole—history, and the outlook of men upon the world, as they are embodied in the histories of words—comparatively few people seem to have written in English. Trench led the way with his little book _On the Study of Words_, which is interesting, both for itself and because the Archbishop was the first to attach as much or more importance to the semantic than to the etymological side of his subject, being, in fact, himself the originator of the _Oxford Dictionary_. Max Müller’s numerous essays and writings are fresh and keen and full of interest. The material adduced by both these writers should always be verified by reference to the _Dictionary_. I do not know if anyone has hitherto attempted to treat the subject chronologically and systematically, apart from one solitary English writer, Mr. Pearsall Smith. To his invaluable little book, _The English Language_ (Home University Library), I am indebted throughout, not only for very much of my material, but also for many extremely fruitful suggestions as to the best way of dealing with it. I have also made extensive use of two essays (“English Words Abroad” and “Four Romantic Words”), printed in _Words and Idioms_ (Constable), of which, as of _The English Language_, it would, in my opinion, be very difficult to speak too highly, partly because of the imaginative treatment of the material and partly because of its solid background of careful scholarship and wide reading. It is a great pleasure to acknowledge here the more direct and personal help which I have been fortunate enough to receive from time to time from this distinguished writer.