Roentgen Ray Intoxication. Iii . T~e Path of a Beam O]~ Hard Rays in Txe Living Organism

l%A~ 45. All roentgenologists are deeply interested in the problems which may be formulated in these few questions: Do the hard x-rays follow a straight and narrow path from the x-ray target through the tissues of the human body? Do these hard x-rays suffer from reflection or refraction and therefore influence tissues outside of this direct path-way? What factor is secondary radiation in the treatment of disease and does such secondary radiation exert a toxic effect on tissue cells or tumor cells outside of the direct pathway of the hard x-rays? The experiments outlined below help to give an answer to the above questions. We may say that our experiments indicate that the hard x-rays which injure the epithelial cells of the intestine travel in straight lines through the host's tissues with no evidence that these rays are deviated to injure tissues outside of the direct x-ray pathway. It is probable that the same rays are concerned in the destruction of cancer cells and that the same statement applies to the path of such x-rays through living tissues. It is obvious that the x-rays which influence the photographic plate or the retina (fluoroscope) travel in straight lines from the target through the living tissues. These rays are limited sharply by lead or other impervious screens. The x-rays which injure superficial epithelium (hard and soft rays) are sharply limited by impervious screens. Theoretically it is impossible to outline the track of a beam of radiation through the deeper living tissues. The following possibilities 731