FIRST REPORT OF T H E COMMITTEE ON PHOTOCHEMISTRY, DIVISIOK O F CHEMISTRY AND CHEMICAL TECHNOLOGY, XATIONAL RESEARCH COUNCIL BY € S. I. TAYLOR
The following six papers represent the initial effort of the Committee on Photochemistry' of the Division of Chemistry and Chemical Technology of the Sationsl Research Council to promote further interest in the problems of photochemistry. During the last two decades the subject has undergone a considerable expansion consequent upon the adoption of newer ideas in the realm of physics with respect to the nature of light, and the processes of its absorption by atoms and molecules. The concept of quanta of light and of quantised absorption by atomic and molecular species has led to an entirely different attitude towards photochemical problems from that which was held in the first decade of the present century. The acceptance of the quantum theory has been more complete upon the part of physicists than by chemists and among the latter there still remains a degree of conservatism with respect to the older concepts. The attempt has been made in the articles which follow to discuss some of the problems of photochemistry from both standpoints. In the article by Professor Bancroft will be found an exposition of what might he termed the classical attitude to photochemical work. On the other hand the mnderr! physical point of view with respect to the absorption process and the changes produced in the absorbing system by the energy absorbed has been stated in its pertinent aspects by Professor L. A. Turner of the Physics Department of Princeton University. The quantum concept, in its relation to the cherni. cal reactions occurring, has formed the subject of Professor Taylor's contribution. Since all quantitative photochemical work must eventually involve the measurement of light absorption and the quantitative evaluation oi light energy incident to the photo-system, this problem has been very comprehensively treated by Professor G. S. Forbes and by Dr. H. de Laszlo. The subject of photochemistry has much in common with the production of chemical reactions by alpha-particles and by other sources of ionisation. This forms the subject of a final article by Professor S. C. Lind. The whole group of contributions is offered in the hope that progress in photochemical research in the United States may be stimulated by their perusal. It is planned to follow this report by others which deal more extensively with particular problems in the field. 1 The Committe is composed of the following members: Professors W.D. Bancrnft, G .S Forbes, S. C. Lind, F. Daniels and H. S. Taylor, chair ma?^. The articles which follow have not been submitted to the Committee as a whole. The individual authors are alone responsible for their respective contributions.
