856
KEW BOOKS
In this brochure, published in the well-known “Ahrens’sche Sammlung,” now edited by Professor Grossmann, one of the foremost workers in the domain of heterogeneous equilibria gives a rapid survey of the principles of the phase rule as applied t o systems of 1 to 5 components, with special reference to systems which are of importance in nature and in industry. The exposition, although necessarily brief, is clear and is made all the more easy to follow by the excellent diagrams which accompany the text. Advanced students will find this an excellent summary of some of the more important applications of the phase rule. ALEX. FINDLAY. Physica (Volume I, No. 1, December, 1933). 24xl6cm.; 96 pp. The Hague: Martinus Nijhoff. To be published in monthly parts, at a price not exceeding 25 guilders for the volume of 960 pages each year. This new periodical takes over part of the title of Physica, Nederlandsch Tijdschrijt voor Natuurkunde, which has been appearing since 1921. The Tijdschrift is to continue publication in Dutch, but the new Physica will contain, in English, French, or German, all original contributions t o physics of t h e Dutch cenbers of research, and will serve also as a continuation of the Archives Nderlandaises des Sciences Exactes et Naturelles. The introduction of a new periodical will be received with, a t best, mixed feelings by all institutions working under strictly limited library allocations. An earlier circular from The Hague points out, however, that the contributions of Dutch physicists will no longer appear in the accustomed foreign, mainly German, periodicals; as the latter are generally sold by weight, it is argued that the advent of Physica will therefore involve no net increase in world expenditure on periodicals. There is incontrovertible logic in this, but the average illogical laboratory dweller will not easily be convinced, and i t is only too likely that the members of his library committee will share his doubts. The inevitable protest against any new periodical, as such, being discharged, it remains to review this latest example on its merits. The first number contains eight papers, covering a wide range of topics: adiabatic cooling of paramagnetic salts in magnetic fields (de Haas, Wiersma, and Kramers); concentration of Na atoms and Na+ ions in the sodium low-voltage arc (Druyvesteyn); emission of light in gas discharges (de Groot); design of quartz-fluorite achromat (van Heel); dipole measurements with very small quantities of material (Henriquez); relative abundance of Li7 and Lie isotopes (Omstein, Vreeswijk, and Wolfsohn); photographic sum rule (van Kreveld); and Tchebycheff polynomials (van der Pol and Weyers). Detailed discussion of these would be out of place here, but it may be said a t once that the new periodical will rank as an important physical journal, with an appeal to a proportion of physical chemists as well as to all physicists. It has a distinguished editorial board, representative of the seven great research institutions of the Netherlands, on which it will rely for its articles. In view of the quantity and quality of the work now issuing in an unbroken stream from these sources, Physica seems assured of success from the outset. H. R. ROBINSON.
