Radioactive Phosphorus in the Diagnosis of Gastrointestinal Cancer W. Vogel & M. Büttner GmbH optical interference continues to be Unterrichts und Medizinal Augelegenheiten optical interference continues to be of great importance in areas such as spectroscopy and metrology are brought to bear with elegance and force ) and a miniature Geiger counter to record the differences in beta emission over tumors as compared to normal tissue now appears clinically useful in the diagnosis of gastrointestinal malignancy where the organ is available for such instrumentation simple survey tests applied periodically to those segments of the population considered most susceptible should be available