Principles of Metallurgy. By Arthur H. Hiorns. (Macmillan and Co.)—This
book is of too technical a character for detailed notice in these columns, but it may be generally commended to those interested in the study. The introductory chapters are devoted to a statement of "Chemical Principles." Following these come chapters on " Alloys," "Slags," " Furnaces," and " Fuel." "Iron and Steel" are then treated of, a supplementary chapter being given to the " Bessemer Process." After these we have "Silver," "Gold" (with the methods of refining), " Plati- num." and the other metals, among which the chapter on '6' Aluminium " offers, of course, special novelties. The well- kno wn difficulty of soldering aluminium is discussed. Professor Richards claims to have discovered a method by which it may be done.