196 | ANNUAL REPORT SMITHSONIAN INSTITUTION, 1946 
tissues; certain thickenings of the skin (plantar warts, keratoses) ; 
disturbed function of certain glands such as salivary and thyroid 
(hyperthyroidism) ; many benign and malignant tumor conditions. 
Just as the mere possession of a knife does not make you a surgeon, 
so the possession of X-ray apparatus or radium does not make you a 
radiation therapist. The safe and efficient application of radiation 
methods in disease requires as much skill and even more training than 
many types of surgery. It also requires recognition of the fact that 
there are many conditions far better treated by nonradiological 
methods and a few which actually are rendered worse by Roentgen 
treatment. 
The rays may be applied to human tissues by a variety of methods 
including external application of the beam, internal (intracavitary) 
application, interstitial application (that is, direct insertion of radium 
or radon seeds into the tissues), and various combinations of these 
methods, all designed to deliver the involved tissues a specific planned 
radiation dose. 
FUTURE DEVELOPMENTS 
The world has seen tremendous advances in the X-ray field during 
the past 50 years but there still are numerous developments, both in 
apparatus and technique, to which physicists and physicians are look- 
ing forward. These include the following: 
1. More efficient recording media, including improved film emulsions, processing 
equipment, and fluorescent screens. 
2. Improved simplified exposure meters and automatic timers. 
3. Finer focal-spot diagnostie tubes. 
4. Greatly improved fluoroscopes, perhaps an electron fluoroscope, and, as a re- 
sult, better, safer X-ray motion pictures. 
5. More widespread use of X-rays in teaching and in preventive medicine (includ- 
ing the installation of X-ray units in morgues to aid in research and routine 
autopsy work). 
6. Improved methods of calculating the size and depth of tumors, so that radiation 
beams may be still more accurately aimed. 
7. Improved selection of patients for both diagnosis and treatment (to reduce 
unnecessary expense and unnecessary exposure of human tissues—especially 
the reproductive organs— to X or gamma rays). 
8. Finally, and most important of all, the training of more and better radiologists, 
medical physicians specializing in X-ray diagnosis and treatment. 
The value of X-rays to science in general and to medicine in par- 
ticular is immense and ever increasing. They have provided us with 
a weapon by which we may search out the structure of matter, as 
well as the hidden components of the body. The diagnosis of innum- 
erable disease conditions is dependent largely or entirely on X-ray 
examinations and the treatment of several types of disease likewise 
requires Roentgen irradiation. The debt of mankind to Roentgen and 
