The Effect of Hard Roentgen Rays and Gamma Rays of Radium

Abstract

One of the principal points of contention in modern radiobiology is the question as to whether in the domain of roentgen and gamma rays the effect is dependent on the wave length; or, in other words, whether by equal quantities of absorbed energy different wave lengths have a different effect. For the rays mostly used in therapy emitted at 50 K.V. without filter to 200 K.V. with 2 mm. copper filter, it is generally admitted that there is no marked difference in effect; but especially in respect of the extremely short waves—shorter than 0.1 Å.—our knowledge is still somewhat incomplete and there are great controversies between various authors. The literature, extensive regarding rays emitted at a tension below 200 K.V., is comparatively scanty for the shorter wave lengths. I shall deal with the literature in broad outline only; completeness not being attainable within the scope of this work, I shall chiefly confine myself to the publications concerning the above-mentioned domain of short waves with which I have met during late years. Among the supporters of the idea of equal effect by the same ionization are: Holthusen and collaborators, who have principally experimented on A scaris eggs and on the human skin; Wood, who has made experiments with inoculations of tumor; Arntzen and Krebs, irradiating seeds of plants; Alberti, investigating cornea epithelium of salamanders; Jacobi (lethal dose for mice); Fricke, Petersen, and Morse (chemical and colloidal reactions); Rothstein (trypsine reaction); Piepenborn (lymph glands); Vierheller and Saralegui (seeds); Packard (Drosophila eggs); Glocker and his collaborators (chemical and biological experiments); Schubert (chick embryo); Groedel and Schneider (yeast and paramecium); Simon (Drosophila eggs); Regaud (testicles); Hess, Grebe and Martius, Sievert, Klein and Gaertner, all of whom have examined the reaction of the human skin. A smaller but still important number of researchers hold the opinion that soft rays have a stronger effect, several of them having investigated the reaction of the skin. Among these are numbered: Wintz and Rump, Glasser and his collaborators, Jona, Stahel, Murdock and Simon, whilst many have made use of other objects. Strangeways and Hopwood (tissue-cultures); Crowther (protozoa); Russ and Scott (tumor); Gunsett, Ancel, and Spack (lentils); Schugt (castration of mice); Holweck and Lacassagne (bacteria, yeast, and protozoa). Adherents of the opinion that hard rays have a greater effect are much fewer in number. I may mention among others: Bolaffio, Reinhard, and Zuppinger, working in the field of biology as well as of chemistry. There are also researchers who believe that there is no definite linear dependency of the effect on the wave length, but that special wave lengths are particularly effective (Dognon and Failla).