The Beilstein Handbook as a source of pre-1960 chemical patent literature

The Beilstein Handbook of Organic Chemistry covered a limited amount of patent literature from its beginning in the 18th century until 1980. Little has been published about the extent of this potentially valuable source of patent literature, especially in the pre-1960 period before many other databases start. This paper discusses the data available, based upon the records for a small number of commercially important chemical compounds, and concludes that there is a substantial amount of unique patent data, especially from the 1930s and 1940s period, from a small range of major countries. In addition, the presence of clusters of patents of similar date and the same assignee suggests that the file may be able to offer a supplement to existing sources of patent family data, for a unique time period. Investigations have been carried out concerning the standard of the STN load of the Beilstein file. The paper also considers the small but significant rate of citation of pre-1960 patents in search reports and how the chronological citation profile differs from the chronological patent records profile in the database. Finally, it discusses possible improvements in access to this older literature.