To return for a moment to the Medical and Anthropological aspects of the Work. Perhaps no single branch of Scientific Enquiry has made such noteworthy strides of late years as Anthropology, and in particular the special Department of that Science devoted to morbid and anomalous manifestations of the sexual appetite,—unnatural lusts, sensual aberrations, sexual inversions, and all the rest. The subject, no doubt, is repulsive, but it is none the less profoundly important from the scientific side, in connexion both with the general advance of our knowledge of Mankind, and with the special Study of Insanity and Madness, as well as from the humanitarian point of view as giving material for the eventual alleviation of many of these manifestations of Mental Disease. Out of a host of names, it is only necessary to mention two, those of Lombroso and Krafft-Ebing, to demonstrate the high place these investigations have vindicated for themselves among the scientific triumphs of the Century that has just closed. On this side the _Geschichte der Lustseuche_ is of the highest importance, supplying as it does innumerable instances of those very phaenomena of morbid sexual perversions that constitute the subject matter of this rapidly progressive branch of Science, one likely in the near future to prove of infinite benefit to afflicted humanity. Of the Author personally there is no need to say much, nor indeed is there much to be said. His life was quiet and uneventful, as a Scholar’s and Savant’s should be. After holding a Professorship at Berlin, he was summoned to fill a similar post at the University of Halle, where he succeeded to the Chair left vacant by the death of the celebrated Dr. Baumgarten-Crusius; and it was here that he completed his great Work,—in spite of difficulties and lack of books, which he naïvely and rather pathetically laments in his Preface. Halle had already been made illustrious by an earlier and even more distinguished worker in the same field, the famous Sprengel (died March 15, 1833), author of a masterly _History of Medicine_ and many other professional works; and with a characteristic touch of Teutonic sentimentality our Author dates the Preface to his own _Geschichte_ on Sprengel’s birth-day. A by no means unimportant feature of Dr. Rosenbaum’s book, and one according well with his patient and laborious methods, is the very extensive and valuable Bibliography, which will be found at the end of the Work. This embraces almost everything that has been written on the subject in all languages, and should prove of inestimable service to the serious student.