nature, because on the whole the katabolic conditions of the environment preponderate over the anabolic. In conclusion, certain psychological and sociological aspects of sex relations are discussed, namely, the occurrence of the love of mates and of offspring among animals, the intellectual and emotional differences between the sexes, and the various proposals for checking increase of population. The authors express strong aversion, based on biological grounds, to the recent attempts of some women to mold their sex into the fashion of men. They hold that the difference between the mental capabilities of women and men is highly beneficial to the race, and is hence to be fostered and not obliterated. Each chapter of the work is followed by a summary of its main points, and a list of books bearing upon the special topic under treatment. The authors have discussed the recently published views of Prof. Weisman on Heredity, and have taken account also of Wallace's latest criticisms on Darwinism. They express regret that limits of space have made it impossible to give the botanical side of their subject its proportionate share of attention, but they have inserted illustrations of the essential facts, which they deem sufficient to show the parallelism of the reproductive processes throughout nature. A defect of the book is in its language, which is frequently so involved as to be obscure, and is still oftener awkward. The volume is illustrated and has an index.
The Metallurgy of Steel. By Henry Marion Howe. Vol. I. New York: The Scientific Publishing Company. Pp. 380, quarto. Price, $10.
In this work metallurgists are provided with an account of the most important of metallurgical industries on a scale which is seldom ventured upon. Its purpose is to describe the present practice of steel-making in America without attempting to give the history of the industry. Hence the author says: "In describing old experiments and abandoned processes, I have not aimed to give matter of historic interest, but rather that which might be useful, whether in deterring others from repeating unnecessary or hopeless experiments, or in guiding them should processes once unsuccessful become commercially possible through changed conditions." Most of the first half of this volume is devoted to the characters of different steels, produced by admixtures of carbon, silicon, manganese, and other metallic and non-metallic elements. In considering the effect of carbon on iron, the author presents both the chemical and the microscopical evidence which goes to show that there are two conditions of combination of carbon with iron. In one of the early chapters the processes of hardening, tempering, and annealing are described, and the changes produced in the metal by these operations are explained. The absorption of gases by iron and their escape from the metal, and the various means taken to prevent the consequent forming of blow-holes and pipes, form a division of the subject that receives full discussion. The author considers next the varieties of stuctureshown by the microscope, and the changes of crystallization, etc., produced by various treatments of the metal. The operations included under cold working and hot working are then described, after which the making of steel is taken up. A great many varieties of the direct process, several charcoal-hearth processes, and the crucible process are described and their results are compared. The closing chapter is a description of the apparatus for the Bessemer process, including a variety of modifications. The material of this volume has been published in supplements to The Engineering and Mining Journal within the past two years, during which time new results have been attained in some departments of the subject. Some of these—namely, on manganese steel and other special steels, on anti-rust coatings, and on lead-quenching—are added in appendixes. In stating the cost of metallurgical processes, the author has generally given the quantities of material and the amount of labor needed for a given work rather than the expense in dollars and cents, for the reasons that the former fluctuate less than the latter, and more managers are willing to tell what quantities of materials they use than what is their exact cost of production. He has inserted a great many references to original authorities, for the purpose of showing that his statements have a solid foundation, or so that the reader may examine any special topic more in detail. In re-
