The wonders which medical workers have already brought about in the diagnosis and treatment of disease suggest that a time may come when the physician will be able to analyze most illnesses as soon as they start, and cure them before damage results. How soon this 'golden age of healing' arrives will depend greatly on how close is the collaboration between research workers in medicine and those who Work in the sciences on which medicine depends. The physician has long relied on the chemist for curative drugs and on the physicist for diagnostic instruments and healing rays. In the one field new materials and in the other new devices are being produced in increasing numbers, helping to make imminent new miracles of medicine. The X-ray and the microscope (显微镜) have extended the vision of the medical observer until he can see through ten inches of living flesh or into a single tissue cell (细胞组织), yet similar but much more powerful tools still await development. Modem electrical devices enable him to listen to faint murmuring of the life processes, or to measure feeble currents arising from heart and brain and nerve yet electrical body measurements are but little understood. Now newly discovered atomic rays are being brought to help him destroy malignant invaders of the human system, and there is every reason to believe that even more curative rays await discovery. It can be inferred from the opening sentence of the first paragraph that medical workers______.