2 Applied Biophysics 



ology, that is, particularly in the applications of radiations to the 

 problems of medicine. This year marks the fiftieth anniversary 

 of the discovery of X-rays by Rontgen, an event of outstanding 

 significance both for pure science and medicine, for it provided 

 the physicist with a most powerful wxapon of research into the 

 structure of matter, and the doctor with almost a new sense, and 

 diagnostic possibilities of the highest order. Later, the rays were 

 recognized as a lethal agent, whose proper power and scope 

 against malignant disease are only now being unfolded. The 

 year 1896 saw the discovery of radioactivity, which again has 

 furnished, besides the most profound studies of the structure of 

 matter, a powerful if still largely mysterious agent in the treat- 

 ment of malignancy. Recently, artificial radioactivity has pro- 

 vided the experimental physiologist with a means of studying 

 metabolic processes, while modern nuclear physics seems destined 

 to influence medicine profoundly as our mastery of atomic tech- 

 niques develops. 



Tt would be easy to show how the classical lines of development 

 of physical inquiry have been followed in medical radiology, the 

 sequence first of qualitative observation, then of attempts at 

 quantitative measurement, disagreement, and final agreement on 

 units of measurement, subsequent discussion of the significance 

 of such units, and the gradual development of mathematical gen- 

 eralization and detailed solution of practical problems. We are 

 here concerned, however, rather with the need for an expanding 

 horizon and the insistence that physics has a wider scope and role 

 in medical thought, research, treatment, and education than so 

 far usually accorded to it. 



This scope of physics in medicine may, for example, be gaged 

 from an encyclopedia of medical physics recently published in 

 the United States. Merely to list the headlines would require 

 many pages, and every branch of medicine and surgery is repre- 

 sented. 



We think, for example, of the many applications of optical 

 principles in medicine and surgery, ranging from the embodiment 

 of laws of geometrical optics in spectacle lenses to laryngoscopes, 

 bronchoscopes, cystoscopes, sometimes of real beauty in design 



