If we pass from the historian's individuality to his materials, we find, that, in a great degree, his facts are discoveries, and that, if his book possessed no literary value whatever, it would still be an' important addition to the history of Europe during the latter part of the sixteenth century. He has, of course, studied all the prominent contemporary chronicles and pamphlets of Holland, Flanders, Spain, France, Germany, and England; and if his materials had been confined to published sources of information, he would still be in possession of facts not generally known or carefully analyzed and combined; but the peculiar value of his History is due to its exhaustive examination, of unpublished private letters and political documents. The archives of Holland, England, and Spain have been opened to his investigations, and he has been particularly fortunate in being able to road the whole correspondence between Philip II., his ministers, and governors, relating to the affairs of the Netherlands, from 1584 to the death of that monarch. Placed thus at the centre from which events radiated, and understanding perfectly the real designs which Spain concealed under a cover of the most diabolical dissimulation, and which are now for the first time completely elucidated, he was able to judge of the mistakes of the other cabinets of Europe, also laid bare to his unwearied research. The study of the manuscripts in the English State-Paper Office, and in the collections of the British Museum, has given him a perfect insight into the characters and policy of the statesmen of the England of Elizabeth; and the exact relations which England bore to Holland and Spain he has for the first time clearly indicated. As a contribution to the history of England, these two volumes are of inestimable value. They will disturb, and in some cases revolutionize, the fixed opinions which the most intelligent Englishmen of the present day have formed of almost every public man of the Elizabethan era; and we cannot but wonder that this work should have been left for an American scholar to accomplish.