rails, sheath-metal, and wire; the casting of iron, zinc, and alloys of copper, into various objects; the spinning and weaving of various fibres, flax, cotton, jute, to be-come materials of greater value; also the manufacturing of paper from rags, of horn into combs, and of bristles into brushes—all these operations belong to this section.
Chemical technology, on the other hand, as Dr. Wagner observes, "deals with the operations by which the raw material is not only changed in its form, but especially as regards its nature; such, for instance, is the case with the extraction of metals from their ores; the conversion of lead into white-lead and sugar of lead (acetate of lead); the conversion of sulphate of baryta into chloride of barium and baryta white (permanent or Chinese white); the conversion of cryolite into sulphate of alumina, alum, and soda; the conversion of rock-salt into sulphate and carbonate of soda; the conversion of carnollite and kainite into chloride and bromide of potassium, sulphate and carbonate of potassa; the conversion of copper into verdigris and sulphate of copper; the manufacture of paraffin, and paraffin or crystal oils from peat, Boghead coal, and lignite; the preparation of kelp and iodine from sea-weeds; the manufacture of stearine-candles (stearic acid properly) and soap from oils and fats; the preparation of sugar and alcohol from starch the conversion of alcohol into vinegar; the brewing of beer from barley and hops; the manufacture of pig-iron into malleable iron (puddling process), and the conversion of malleable iron into steel; the production of gas, coke, and tar from coals; the extraction from the tar of such substances as benzol, carbolic acid, aniline, anthracen, asphalte, naphthaline; the preparation of tar-colors, as rosaniline, aniline blue, Manchester yellow, Magdala red, alizarine, iodine green, picric acid, etc."
These illustrations of the scope and character of chemical technology give also an idea of the quality and range of Dr. Wagner's book. For twenty years he has held an eminent position in Germany as an authority upon technology, and his voluminous annual reports upon the subject have been the standards of reference in regard to its progress. The first edition
of the present hand-book was published in 1850; and the eighth edition, which appeared last year, is now translated, and is the first that appears in English. The volume is a compact cyclopædia of the most recent and accurate knowledge on a wide range of practical subjects, and will be of great value to the industrial and manufacturing interests of the country.
The Great Problem: The Higher Ministry of Nature viewed in the Light of Modern Science and as an Aid to Advanced Christian Philosophy. By John R. Leifchild, A.M., author of "Our Coal-Fields and our Coal-Pits," "Cornwall: Its Mines and Miners," etc., etc. With an introduction by Howard Crosby, D.D., LL.D., Chancellor of the University of New York. 543 pages. George P. Putnam & Sons.
Mr. Leifchild's book, entitled "The Higher Ministry of Nature," has been re-published by the Putnams, who have appropriately prefixed to it the title "The Great Problem." The general aim of the author, who is a semi-preacher and semi-geologist of London, is to show that the higher teachings of Nature confirm true religious faith instead of subverting it; but he feels it incumbent upon him to go into all the controverted questions of the time in theology, metaphysics, and science, and is equally ready in the treatment of theism, pantheism, the unknowable, Spinozism, Darwinism, evolution, morals, the correlation of forces, protoplasm, and other knotty matters too numerous to mention.
The American volume comes well commended to the public. A gentleman high in the honors of scholarship, and the responsibilities of education, and who presides over our metropolitan university, has prepared a compact and telling introduction to Mr. Leifchild's volume, in which he assures us that it is a work that strips off disguises and goes to the core of things. His decisive views are put in a narrow compass, so that we are happily enabled to give them complete to the readers of the Monthly. If any should happen to think that the volume lacks point and incisiveness, they will find this quality eminently supplied in the chancellor's brief prologue. When, however, he calls for a thousand such books, we