The general interest which has been aroused the last few years in physical chemistry is reflected in the number of books which have appeared in this department. Some of these dwell more upon the older physical chemistry, devoting but relatively little space to the later developments, while others are chiefly concerned with the newer phases of the subject. Perhaps the most satisfactory book which has appeared along this line is Walker's 'Introduction to Physical Chemistry' (Macmillan). No attempt is made to exhaust the field but the subject is well covered. Especially commendable is the clearness of the book, which will render it useful to students. The non-mathematical treatment of the subject will also commend it to many who use it as an introduction to physical chemistry. A book of narrower scope is Dr. H. C. Jones's 'Theory of Electrolytic Dissociation and Some of Its Applications,' from the press of the same publishers. The author gives first a short review of the development of physical chemistry up to the days of van't Hoff, and then surveys the origin of the theory of electrolytic dissociation, its proofs and some of its applications. While making no pretense to cover the whole field of physical chemistry, the author furnishes a very readable account of the most important of the later generalizations. It is a book which should be read especially by those chemists and physicists who are working in other fields, that they may gain a fair view of the electrolytic dissociation theory written by one thoroughly competent for his task. Biologists, too, will find the latter part of the book, treating of the applications of the theory to animal and plant life, of especial interest. Dr. Jones, with S. H. King, has also translated Biltz on 'Practical Methods of Determining Molecular Weights.' This is a successful attempt to gather together the best of the different methods of real value, and it is very satisfactorily carried out, presenting a good guide book for students.
In the production of text-books of general chemistry, there seems to be a little lull, very few books having appeared in recent months. The first part of what promises to be a somewhat original work on inorganic chemistry, by Dr. Sperber, has appeared. After the introduction on general chemical laws, the elements of the seventh group (chlorine, etc.), are first considered, and then their hydrogen compounds; the sixth group (oxygen, etc.) and its hydrogen compounds; fifth group (nitrogen, etc.), etc. The method used is purely inductive, each subject being introduced by experiments from which the underlying principles are developed.
A third edition of Elliott and Ferguson's 'Qualitative Analysis' has appeared which is a considerable improvement upon the previous editions. The principal merit of this book, is in the opinion of many its greatest drawback. In clearness and minuteness of directions it is hardly by any manual of qualitative analysis, and thus it is a particularly easy book for the instructor to use, especially with a large class. But this, on the other hand, cannot fail to encourage mere mechanical work on the part of the student and to discourage independence. With large classes, however, it is a difficult problem how best to cultivate individuality of work.
A little manual of 'Analysis of White Paints,' by G. H. Ellis, will prove of value to chemists to whom now and