Page:Popular Science Monthly Volume 40.djvu/576

558 springs from the absence of a natural and rational system of classification, such as long since was introduced in the organic worlds. Not that attempts at this needed classification have been wanting. Two rival schools for many years have contended for methods diametrically opposed. The so-called natural-history or mineralogical method was advocated by Werner, Mohs, Jameson, Shepard, and Breithaupt; the chemical method, as formulated by Berzelius and developed by Rammelsberg, has been the basis of the text-books of Phillips, Dana, and Naumann. The possibility of reconciling these apparently antagonistic systems has been the aim of our author throughout his long career of study. Labors in this direction, which from time to time have been brought to the attention of the scientific world, are in the present volume connected and completed, forming what he terms a natural system of classification. He approaches his main task by a presentation of those elementary principles of chemistry and physics which underlie alike the two rival methods hitherto in the field. He discusses the nature of chemical combination, of which he holds that solution is a phase; the periodic law; and the important problem of ascertaining the relative degree of chemical condensation, upon which depends the varying hardness and insolubility of species. Between the physical characteristics and the chemical constitution of a mineral subsist necessary relations; on these rest the new classification, in which the seeming contradictions of the two rival schools are brought to accord. In place of the old trivial names we are given a classic Latin nomenclature for classes, orders, genera, and species—that for species being binomial. This system realizes, in a simplified form, that projected by Breithaupt and left unfinished by him. An examination of his nomenclature, as well as of those proposed by Mohs and by Dana, is followed by a synopsis of native species, with both their scientific and trivial names. This is succeeded by a critical discussion of the more important genera and species. In his two concluding chapters Dr. Hunt presents original and striking views of the genesis of carbonaceous minerals—graphite, diamond, petroleum, and coal; and, further, upon the mineral history of natural waters. In his preface our author announces his intention of preparing a descriptive mineralogy based upon this new classification.

author of this book is Director of the Kestner Museum in Hanover. His purpose in writing it has been to present the results of Schliemann's Excavations in a concise form, which should make them more accessible to the general public; and the work appears to have been undertaken with the sanction of the discoverer. He has also sought, by careful discussion and comparisons, to find what are the ascertained results, and to present them free from the conjectures and enthusiastic speculations with which Schliemann's first reports, from the nature of the conditions under which they were written, are necessarily encumbered. The author was engaged in Grecian archæological excavation at Pergamos when he was intrusted with the preparation of the work. He improved the opportunity he then had of making personal observations on the spot, and of informing himself by intercourse with the persons concerned. The undertaking was a difficult one, for the questions which Dr. Schliemann's activity had called up are still undecided, and additions to our knowledge on the subject are constantly furnished by further excavations. But it was pleasant, for these objective studies in Greek antiquity have a charm that is surpassed in no other pursuit. In the account of Troy the history is given of the controversy of the two rival sites, the topography is compared with the references in the Iliad, and the reasons are given—all in seventy-five pages—for believing conclusively that Homer's Troy was real and Schliemann's identification of it is correct. Tiryns is described, in forty pages, as affording the most ancient illustrations of the civilization of which Mycenæ has furnished so numerous and so splendid examples. The largest space is given to Mycenæ, with its remarkable tomb-structures and treasurechambers, and its truly astounding richness