Concerning one system of classification and codification of organic reactions

THE major abstracts journals, which are concerned with exhaustive abstracting of the world's chemical literature, play an outstanding part in the development of all branches of chemistry. Their significance is not restricted to the fact that i11 their comparatively small scope are concentrated all the essential results of researches published in more than seven thousand periodicals, scattered over the whole world. No less important is the work done by the abstracts journals of systematizing data accumulated in various fields, with the aim of making them accessible to the chemist who is interested in a completely defined category of information. The continuous disordered flow of information which is constantly appearing on the pages of abstracts journals is broadly classified according to the various fields of research existing in chemistry. However, in the systematization of data, such classification represents only the first stage of comparatively coarse sorting of papers by their general field. The basic work of systematizing data is covered in the process of compiling the various indexes to the annual collected editions of the abstracts journals. During this, information of varying character, contained in papers in most diverse fields, is sorted into sufficiently similar groups and sub-groups of information, with subsequent setting out of items of information within each group, in a certain order on the basis of a suitable classification sign. Consequently the indexes allow the chemist not only to tind quickly certain necessary information, but also to get a clear idea of a whole--more or less narrow--range of chemical data. It follows that the indexes of chemical abstracts journals, being real 'keys' to world chemical literature, have, as well as great practical significance, considerable methodical significance, by virtue of the fact that, to a significant extent, they are preparing the work of correlation and generalization of the data obtained in various fields of chemistry. In this sense the indexes serve as a connecting link between chemical literature and the monographic surveys on various chemical problems, which are so important for the development of chemistry. In 1953, the Soviet abstracts journal Chemistry (Khimiya), edited by the Institute of Scientific Information of the Academy of Sciences of the U.S.S.R., joined the small number of the major chemical abstracts journals. The first result of the great attention which was paid to the questions of systematization, on getting ready to publish the new journal, was the development of a classification system, more detailed than the systems accepted in Chemisches Zentralblatt and Chemical Abstracts. At the same time, the study of questions connected with the compiling of indexes was begun in the Institute of Scientific Information of the Academy of Sciences. The basis of the traditional indexing principles which are used at the present time by chemical abstracts journals, was initially established by the subject and formula indexes of