TEXT-BOOKS of physical chemistry are generally written by chemists, which is natural enough, since the subject is much more widely studied by chemists than by physicists. It is therefore a pleasant change to come across a text-book of physical chemistry written by a physicist. As one might expect, the treatment is less descriptive and more mathematical, with greater precision in the definition of physical magnitudes and greater strictness in the deductions. The work under review is an excellent example of this type, being brief, pointed, and consistent. It is not exactly a book which the young chemist without previous knowledge of the subject would be likely to read with profit, but it can be warmly recommended to those who, either by hearing a course of lectures, or bv the perusal of one of the more chemical text-books, have attained some acquaintance with the subject-matter and desire to systematise their knowledge.
Text-book of Physical Chemistry, Theory and Practice.
By Dr. Arthur W. Ewell. Pp. ix+370. (Philadelphia: P. Blakiston, Son and Co., 1909.) Price 2.25 dollars net.