Photochemische Versuchstechnik

Abstract

THE first edition of Plotnikow's book was published in 1911, and the present edition, for the most part, is simply a reproduction made by photomechanical methods. Those who are acquainted with the first edition know that its main characteristics consist in the description of apparatus devised and of methods used by Plotnikow, comparatively little attention being paid to the work of other investigators. Much the same course is pursued in the following additions incorporated in the present volume. Pages 93–106 consist of descriptions of new, ‘light thermostats’ and apparatus for exposure to light on a large scale devised by the author. Pages 202–226 describe methods for the measurement: (a) of the energy of radiation, (b) of absorption coefficients, (c) of light intensities by the tube photometer, (d) of the Schwarzschild constant. Tn connexion with the latter constant it is mainly Plotnikow's own methods to which reference is made, and no mention occurs of the accurate methods which have been used, for example, in very extended investigations in the Kodak laboratories. Pages 254–268 contain additions to the various lecture experiments described in the first edition, and pages 416–438 contain new tables of the absorption coefficients of solutions of various substances. There are very few additions to the literature references given in the re-printed part of the book, and the references to the new parts are very far from complete. Apparently no corrections have been made in the older parts; for example, it is still stated that the action of light on silver chloride gives rise to sub-chloride.

Photochemische Versuchstechnik.

Von Prof. Dr. J. Plotnikow. Zweite, erweiterte, auf photomechanischem Wege hergestellte Auflage. Pp. xvi + 454 + 3 Tafeln. (Leipzig: Akademische Verlagsgesellschaft m.b.H., 1928.) n.p.