Our ‘Diagnostic Tables for the Common Medical Bacteria’ were originally published in the Journal of Hygiene. The tables seemed to fill a need and the demand for reprints was so great that Cambridge University Press reprinted them in pamphlet form.

Many inquired about the technical methods, and there were constant complaints that the methods were not described and that the text lacked details of the taxonomic problems. We resolved, therefore, to expand the original paper and to prepare a book which would give sufficient detail of media and methods to justify its description as a laboratory manual.

Although designed for medical workers we hope that others will use it.

The value of a laboratory manual was impressed on one of us in 1935 at the British Postgraduate Medical School. Dr A. A. Miles had prepared a loose-leaf mimeographed manual to supplement (and improve on) a popular laboratory handbook. With this example in mind a manual suited to the special needs of the National Collection of Type Cultures was prepared, and contributions were made by other members of the Collection staff, particularly Mrs P. H. Clarke, Miss H. E. Ross, Miss C. Shaw, and Mr C. S. Brindle. The National Collection Manual in turn became the basis for the appendices to the present Manual.