This dataset contains records of the BGS analytical chemistry laboratories prior to the year 2000. It is basically an archive of original records and includes card indexes, files and raw analytical data. Files may contain background detail on the samples themselves but coverage is variable; information has been collected over many years in different formats. Different analytical techniques have been used over the years; consequently data are of variable quality as systems have improved with time. Samples analysed could be from anywhere in the world and were usually analysed for internal BGS customers. These are paper records and are available for viewing or copying. Any constraints on data usage would be dependant on individual files. Anyone wishing to access the records would require assistance from staff familiar with the data.