The major reason forpresentingabiblio ultraviolet light, or which make only a casual graphy on fluorescence and phosphorescence reference to the fluorescence technique were can be summed up in one statement: A recent usually rejected. However, occasionally survey showed that twenty-two percent of all papers of this nature were included because chemical and clinical research was uninten fluorescence methods seem to have unusual tionally duplicated. A comprehensive source potential for the problems discussed. Again, if pertinent papers were missed the authors book of fluorescence and phosphorescence would be grateful to have these omissions techniques is therefore needed not only to suggest ideas for future research, but to help called to their attention. The abbreviations of journal names em decrease needless duplication and expense, ployed in this Guide are those used by and thus to promote the development of both disciplines. Chemical Abstracts. Each paper has been The authors hope that researchers new given an alpha-numericalidentification. Sec to fluorescence techniques will appreciate tion A contains papers published in theyears the convenience of this Guide for obtaining 1950-1953, section B the years 1954-1956, data which otherwise could be found only by section C the years 1957-1959, and section reviewing dozens of papers, many difficult to D the years 1960-1964. Section E contains find, and that old hands will find ita valuable papers missed in the original compilation.

The Guide to Fluorescence Literature is designed to free in vestigators and analysts of the tedious task of literature searching. It is disturbing to learn that duplication of research is still quite common. Martyn has reported that 31 percentofall researchers would have acted differentlyhad theyknown all that was known about the subject matter of their projects when they started them [New Scientist 21(377):338(1964)]. There are also reports indicating that the literature explosion has increased the gap between published reports and broad knowledge of their existence. It seems logical to assume that at least one-quarter of each research budget is wasted today because of duplicated effort. An exhaustive literature search should therefore be aprerequisite for any new research project. The Guide is intended to facilitate this task. The Guide is also intended to save valuable time and by call ing attention to articles in journals not available in the researcher's library and by indicating who else is working in the field and what they are doing. The Guide will assist in documenting papers and in pinpointing new concepts. Readers' comments on the first two volumes have been re warding and also an inspiration to improve the Guide further. Vol ume 3 contains a number of innovations that refine its organization and thus increase its usefulness. The most noticeable improve mentis the subgrouping of related papers into narrower categories.