I have been asked to write a foreword to the next edition of the Vademecum of Clinical Bio chemistry renamed to Differential Diagnosis by Laboratory Medicine. The Editor in-Chief, Professor Dusan Mesko, conceived the idea of the Vademecum during a very intensely, in tellectually active period as a visiting Olga Havel Fellow from Slovak Republic at the Mayo Clinic in Rochester. It was here during his study stay that much of the conceptual planning and detailed realization was being completed. It was with much interest that I observed Professor Mesko in his effort, and I know while here he has...